[VOL-4291] Rw-core updates for gRPC migration

Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/google.golang.org/protobuf/reflect/protoreflect/type.go b/vendor/google.golang.org/protobuf/reflect/protoreflect/type.go
new file mode 100644
index 0000000..8e53c44
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/reflect/protoreflect/type.go
@@ -0,0 +1,665 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package protoreflect
+
+// Descriptor provides a set of accessors that are common to every descriptor.
+// Each descriptor type wraps the equivalent google.protobuf.XXXDescriptorProto,
+// but provides efficient lookup and immutability.
+//
+// Each descriptor is comparable. Equality implies that the two types are
+// exactly identical. However, it is possible for the same semantically
+// identical proto type to be represented by multiple type descriptors.
+//
+// For example, suppose we have t1 and t2 which are both MessageDescriptors.
+// If t1 == t2, then the types are definitely equal and all accessors return
+// the same information. However, if t1 != t2, then it is still possible that
+// they still represent the same proto type (e.g., t1.FullName == t2.FullName).
+// This can occur if a descriptor type is created dynamically, or multiple
+// versions of the same proto type are accidentally linked into the Go binary.
+type Descriptor interface {
+	// ParentFile returns the parent file descriptor that this descriptor
+	// is declared within. The parent file for the file descriptor is itself.
+	//
+	// Support for this functionality is optional and may return nil.
+	ParentFile() FileDescriptor
+
+	// Parent returns the parent containing this descriptor declaration.
+	// The following shows the mapping from child type to possible parent types:
+	//
+	//	╔═════════════════════╤═══════════════════════════════════╗
+	//	║ Child type          │ Possible parent types             ║
+	//	╠═════════════════════╪═══════════════════════════════════╣
+	//	║ FileDescriptor      │ nil                               ║
+	//	║ MessageDescriptor   │ FileDescriptor, MessageDescriptor ║
+	//	║ FieldDescriptor     │ FileDescriptor, MessageDescriptor ║
+	//	║ OneofDescriptor     │ MessageDescriptor                 ║
+	//	║ EnumDescriptor      │ FileDescriptor, MessageDescriptor ║
+	//	║ EnumValueDescriptor │ EnumDescriptor                    ║
+	//	║ ServiceDescriptor   │ FileDescriptor                    ║
+	//	║ MethodDescriptor    │ ServiceDescriptor                 ║
+	//	╚═════════════════════╧═══════════════════════════════════╝
+	//
+	// Support for this functionality is optional and may return nil.
+	Parent() Descriptor
+
+	// Index returns the index of this descriptor within its parent.
+	// It returns 0 if the descriptor does not have a parent or if the parent
+	// is unknown.
+	Index() int
+
+	// Syntax is the protobuf syntax.
+	Syntax() Syntax // e.g., Proto2 or Proto3
+
+	// Name is the short name of the declaration (i.e., FullName.Name).
+	Name() Name // e.g., "Any"
+
+	// FullName is the fully-qualified name of the declaration.
+	//
+	// The FullName is a concatenation of the full name of the type that this
+	// type is declared within and the declaration name. For example,
+	// field "foo_field" in message "proto.package.MyMessage" is
+	// uniquely identified as "proto.package.MyMessage.foo_field".
+	// Enum values are an exception to the rule (see EnumValueDescriptor).
+	FullName() FullName // e.g., "google.protobuf.Any"
+
+	// IsPlaceholder reports whether type information is missing since a
+	// dependency is not resolved, in which case only name information is known.
+	//
+	// Placeholder types may only be returned by the following accessors
+	// as a result of unresolved dependencies or weak imports:
+	//
+	//	╔═══════════════════════════════════╤═════════════════════╗
+	//	║ Accessor                          │ Descriptor          ║
+	//	╠═══════════════════════════════════╪═════════════════════╣
+	//	║ FileImports.FileDescriptor        │ FileDescriptor      ║
+	//	║ FieldDescriptor.Enum              │ EnumDescriptor      ║
+	//	║ FieldDescriptor.Message           │ MessageDescriptor   ║
+	//	║ FieldDescriptor.DefaultEnumValue  │ EnumValueDescriptor ║
+	//	║ FieldDescriptor.ContainingMessage │ MessageDescriptor   ║
+	//	║ MethodDescriptor.Input            │ MessageDescriptor   ║
+	//	║ MethodDescriptor.Output           │ MessageDescriptor   ║
+	//	╚═══════════════════════════════════╧═════════════════════╝
+	//
+	// If true, only Name and FullName are valid.
+	// For FileDescriptor, the Path is also valid.
+	IsPlaceholder() bool
+
+	// Options returns the descriptor options. The caller must not modify
+	// the returned value.
+	//
+	// To avoid a dependency cycle, this function returns a proto.Message value.
+	// The proto message type returned for each descriptor type is as follows:
+	//	╔═════════════════════╤══════════════════════════════════════════╗
+	//	║ Go type             │ Protobuf message type                    ║
+	//	╠═════════════════════╪══════════════════════════════════════════╣
+	//	║ FileDescriptor      │ google.protobuf.FileOptions              ║
+	//	║ EnumDescriptor      │ google.protobuf.EnumOptions              ║
+	//	║ EnumValueDescriptor │ google.protobuf.EnumValueOptions         ║
+	//	║ MessageDescriptor   │ google.protobuf.MessageOptions           ║
+	//	║ FieldDescriptor     │ google.protobuf.FieldOptions             ║
+	//	║ OneofDescriptor     │ google.protobuf.OneofOptions             ║
+	//	║ ServiceDescriptor   │ google.protobuf.ServiceOptions           ║
+	//	║ MethodDescriptor    │ google.protobuf.MethodOptions            ║
+	//	╚═════════════════════╧══════════════════════════════════════════╝
+	//
+	// This method returns a typed nil-pointer if no options are present.
+	// The caller must import the descriptorpb package to use this.
+	Options() ProtoMessage
+
+	doNotImplement
+}
+
+// FileDescriptor describes the types in a complete proto file and
+// corresponds with the google.protobuf.FileDescriptorProto message.
+//
+// Top-level declarations:
+// EnumDescriptor, MessageDescriptor, FieldDescriptor, and/or ServiceDescriptor.
+type FileDescriptor interface {
+	Descriptor // Descriptor.FullName is identical to Package
+
+	// Path returns the file name, relative to the source tree root.
+	Path() string // e.g., "path/to/file.proto"
+	// Package returns the protobuf package namespace.
+	Package() FullName // e.g., "google.protobuf"
+
+	// Imports is a list of imported proto files.
+	Imports() FileImports
+
+	// Enums is a list of the top-level enum declarations.
+	Enums() EnumDescriptors
+	// Messages is a list of the top-level message declarations.
+	Messages() MessageDescriptors
+	// Extensions is a list of the top-level extension declarations.
+	Extensions() ExtensionDescriptors
+	// Services is a list of the top-level service declarations.
+	Services() ServiceDescriptors
+
+	// SourceLocations is a list of source locations.
+	SourceLocations() SourceLocations
+
+	isFileDescriptor
+}
+type isFileDescriptor interface{ ProtoType(FileDescriptor) }
+
+// FileImports is a list of file imports.
+type FileImports interface {
+	// Len reports the number of files imported by this proto file.
+	Len() int
+	// Get returns the ith FileImport. It panics if out of bounds.
+	Get(i int) FileImport
+
+	doNotImplement
+}
+
+// FileImport is the declaration for a proto file import.
+type FileImport struct {
+	// FileDescriptor is the file type for the given import.
+	// It is a placeholder descriptor if IsWeak is set or if a dependency has
+	// not been regenerated to implement the new reflection APIs.
+	FileDescriptor
+
+	// IsPublic reports whether this is a public import, which causes this file
+	// to alias declarations within the imported file. The intended use cases
+	// for this feature is the ability to move proto files without breaking
+	// existing dependencies.
+	//
+	// The current file and the imported file must be within proto package.
+	IsPublic bool
+
+	// IsWeak reports whether this is a weak import, which does not impose
+	// a direct dependency on the target file.
+	//
+	// Weak imports are a legacy proto1 feature. Equivalent behavior is
+	// achieved using proto2 extension fields or proto3 Any messages.
+	IsWeak bool
+}
+
+// MessageDescriptor describes a message and
+// corresponds with the google.protobuf.DescriptorProto message.
+//
+// Nested declarations:
+// FieldDescriptor, OneofDescriptor, FieldDescriptor, EnumDescriptor,
+// and/or MessageDescriptor.
+type MessageDescriptor interface {
+	Descriptor
+
+	// IsMapEntry indicates that this is an auto-generated message type to
+	// represent the entry type for a map field.
+	//
+	// Map entry messages have only two fields:
+	//	• a "key" field with a field number of 1
+	//	• a "value" field with a field number of 2
+	// The key and value types are determined by these two fields.
+	//
+	// If IsMapEntry is true, it implies that FieldDescriptor.IsMap is true
+	// for some field with this message type.
+	IsMapEntry() bool
+
+	// Fields is a list of nested field declarations.
+	Fields() FieldDescriptors
+	// Oneofs is a list of nested oneof declarations.
+	Oneofs() OneofDescriptors
+
+	// ReservedNames is a list of reserved field names.
+	ReservedNames() Names
+	// ReservedRanges is a list of reserved ranges of field numbers.
+	ReservedRanges() FieldRanges
+	// RequiredNumbers is a list of required field numbers.
+	// In Proto3, it is always an empty list.
+	RequiredNumbers() FieldNumbers
+	// ExtensionRanges is the field ranges used for extension fields.
+	// In Proto3, it is always an empty ranges.
+	ExtensionRanges() FieldRanges
+	// ExtensionRangeOptions returns the ith extension range options.
+	//
+	// To avoid a dependency cycle, this method returns a proto.Message value,
+	// which always contains a google.protobuf.ExtensionRangeOptions message.
+	// This method returns a typed nil-pointer if no options are present.
+	// The caller must import the descriptorpb package to use this.
+	ExtensionRangeOptions(i int) ProtoMessage
+
+	// Enums is a list of nested enum declarations.
+	Enums() EnumDescriptors
+	// Messages is a list of nested message declarations.
+	Messages() MessageDescriptors
+	// Extensions is a list of nested extension declarations.
+	Extensions() ExtensionDescriptors
+
+	isMessageDescriptor
+}
+type isMessageDescriptor interface{ ProtoType(MessageDescriptor) }
+
+// MessageType encapsulates a MessageDescriptor with a concrete Go implementation.
+// It is recommended that implementations of this interface also implement the
+// MessageFieldTypes interface.
+type MessageType interface {
+	// New returns a newly allocated empty message.
+	// It may return nil for synthetic messages representing a map entry.
+	New() Message
+
+	// Zero returns an empty, read-only message.
+	// It may return nil for synthetic messages representing a map entry.
+	Zero() Message
+
+	// Descriptor returns the message descriptor.
+	//
+	// Invariant: t.Descriptor() == t.New().Descriptor()
+	Descriptor() MessageDescriptor
+}
+
+// MessageFieldTypes extends a MessageType by providing type information
+// regarding enums and messages referenced by the message fields.
+type MessageFieldTypes interface {
+	MessageType
+
+	// Enum returns the EnumType for the ith field in Descriptor.Fields.
+	// It returns nil if the ith field is not an enum kind.
+	// It panics if out of bounds.
+	//
+	// Invariant: mt.Enum(i).Descriptor() == mt.Descriptor().Fields(i).Enum()
+	Enum(i int) EnumType
+
+	// Message returns the MessageType for the ith field in Descriptor.Fields.
+	// It returns nil if the ith field is not a message or group kind.
+	// It panics if out of bounds.
+	//
+	// Invariant: mt.Message(i).Descriptor() == mt.Descriptor().Fields(i).Message()
+	Message(i int) MessageType
+}
+
+// MessageDescriptors is a list of message declarations.
+type MessageDescriptors interface {
+	// Len reports the number of messages.
+	Len() int
+	// Get returns the ith MessageDescriptor. It panics if out of bounds.
+	Get(i int) MessageDescriptor
+	// ByName returns the MessageDescriptor for a message named s.
+	// It returns nil if not found.
+	ByName(s Name) MessageDescriptor
+
+	doNotImplement
+}
+
+// FieldDescriptor describes a field within a message and
+// corresponds with the google.protobuf.FieldDescriptorProto message.
+//
+// It is used for both normal fields defined within the parent message
+// (e.g., MessageDescriptor.Fields) and fields that extend some remote message
+// (e.g., FileDescriptor.Extensions or MessageDescriptor.Extensions).
+type FieldDescriptor interface {
+	Descriptor
+
+	// Number reports the unique number for this field.
+	Number() FieldNumber
+	// Cardinality reports the cardinality for this field.
+	Cardinality() Cardinality
+	// Kind reports the basic kind for this field.
+	Kind() Kind
+
+	// HasJSONName reports whether this field has an explicitly set JSON name.
+	HasJSONName() bool
+
+	// JSONName reports the name used for JSON serialization.
+	// It is usually the camel-cased form of the field name.
+	// Extension fields are represented by the full name surrounded by brackets.
+	JSONName() string
+
+	// TextName reports the name used for text serialization.
+	// It is usually the name of the field, except that groups use the name
+	// of the inlined message, and extension fields are represented by the
+	// full name surrounded by brackets.
+	TextName() string
+
+	// HasPresence reports whether the field distinguishes between unpopulated
+	// and default values.
+	HasPresence() bool
+
+	// IsExtension reports whether this is an extension field. If false,
+	// then Parent and ContainingMessage refer to the same message.
+	// Otherwise, ContainingMessage and Parent likely differ.
+	IsExtension() bool
+
+	// HasOptionalKeyword reports whether the "optional" keyword was explicitly
+	// specified in the source .proto file.
+	HasOptionalKeyword() bool
+
+	// IsWeak reports whether this is a weak field, which does not impose a
+	// direct dependency on the target type.
+	// If true, then Message returns a placeholder type.
+	IsWeak() bool
+
+	// IsPacked reports whether repeated primitive numeric kinds should be
+	// serialized using a packed encoding.
+	// If true, then it implies Cardinality is Repeated.
+	IsPacked() bool
+
+	// IsList reports whether this field represents a list,
+	// where the value type for the associated field is a List.
+	// It is equivalent to checking whether Cardinality is Repeated and
+	// that IsMap reports false.
+	IsList() bool
+
+	// IsMap reports whether this field represents a map,
+	// where the value type for the associated field is a Map.
+	// It is equivalent to checking whether Cardinality is Repeated,
+	// that the Kind is MessageKind, and that Message.IsMapEntry reports true.
+	IsMap() bool
+
+	// MapKey returns the field descriptor for the key in the map entry.
+	// It returns nil if IsMap reports false.
+	MapKey() FieldDescriptor
+
+	// MapValue returns the field descriptor for the value in the map entry.
+	// It returns nil if IsMap reports false.
+	MapValue() FieldDescriptor
+
+	// HasDefault reports whether this field has a default value.
+	HasDefault() bool
+
+	// Default returns the default value for scalar fields.
+	// For proto2, it is the default value as specified in the proto file,
+	// or the zero value if unspecified.
+	// For proto3, it is always the zero value of the scalar.
+	// The Value type is determined by the Kind.
+	Default() Value
+
+	// DefaultEnumValue returns the enum value descriptor for the default value
+	// of an enum field, and is nil for any other kind of field.
+	DefaultEnumValue() EnumValueDescriptor
+
+	// ContainingOneof is the containing oneof that this field belongs to,
+	// and is nil if this field is not part of a oneof.
+	ContainingOneof() OneofDescriptor
+
+	// ContainingMessage is the containing message that this field belongs to.
+	// For extension fields, this may not necessarily be the parent message
+	// that the field is declared within.
+	ContainingMessage() MessageDescriptor
+
+	// Enum is the enum descriptor if Kind is EnumKind.
+	// It returns nil for any other Kind.
+	Enum() EnumDescriptor
+
+	// Message is the message descriptor if Kind is
+	// MessageKind or GroupKind. It returns nil for any other Kind.
+	Message() MessageDescriptor
+
+	isFieldDescriptor
+}
+type isFieldDescriptor interface{ ProtoType(FieldDescriptor) }
+
+// FieldDescriptors is a list of field declarations.
+type FieldDescriptors interface {
+	// Len reports the number of fields.
+	Len() int
+	// Get returns the ith FieldDescriptor. It panics if out of bounds.
+	Get(i int) FieldDescriptor
+	// ByName returns the FieldDescriptor for a field named s.
+	// It returns nil if not found.
+	ByName(s Name) FieldDescriptor
+	// ByJSONName returns the FieldDescriptor for a field with s as the JSON name.
+	// It returns nil if not found.
+	ByJSONName(s string) FieldDescriptor
+	// ByTextName returns the FieldDescriptor for a field with s as the text name.
+	// It returns nil if not found.
+	ByTextName(s string) FieldDescriptor
+	// ByNumber returns the FieldDescriptor for a field numbered n.
+	// It returns nil if not found.
+	ByNumber(n FieldNumber) FieldDescriptor
+
+	doNotImplement
+}
+
+// OneofDescriptor describes a oneof field set within a given message and
+// corresponds with the google.protobuf.OneofDescriptorProto message.
+type OneofDescriptor interface {
+	Descriptor
+
+	// IsSynthetic reports whether this is a synthetic oneof created to support
+	// proto3 optional semantics. If true, Fields contains exactly one field
+	// with HasOptionalKeyword specified.
+	IsSynthetic() bool
+
+	// Fields is a list of fields belonging to this oneof.
+	Fields() FieldDescriptors
+
+	isOneofDescriptor
+}
+type isOneofDescriptor interface{ ProtoType(OneofDescriptor) }
+
+// OneofDescriptors is a list of oneof declarations.
+type OneofDescriptors interface {
+	// Len reports the number of oneof fields.
+	Len() int
+	// Get returns the ith OneofDescriptor. It panics if out of bounds.
+	Get(i int) OneofDescriptor
+	// ByName returns the OneofDescriptor for a oneof named s.
+	// It returns nil if not found.
+	ByName(s Name) OneofDescriptor
+
+	doNotImplement
+}
+
+// ExtensionDescriptor is an alias of FieldDescriptor for documentation.
+type ExtensionDescriptor = FieldDescriptor
+
+// ExtensionTypeDescriptor is an ExtensionDescriptor with an associated ExtensionType.
+type ExtensionTypeDescriptor interface {
+	ExtensionDescriptor
+
+	// Type returns the associated ExtensionType.
+	Type() ExtensionType
+
+	// Descriptor returns the plain ExtensionDescriptor without the
+	// associated ExtensionType.
+	Descriptor() ExtensionDescriptor
+}
+
+// ExtensionDescriptors is a list of field declarations.
+type ExtensionDescriptors interface {
+	// Len reports the number of fields.
+	Len() int
+	// Get returns the ith ExtensionDescriptor. It panics if out of bounds.
+	Get(i int) ExtensionDescriptor
+	// ByName returns the ExtensionDescriptor for a field named s.
+	// It returns nil if not found.
+	ByName(s Name) ExtensionDescriptor
+
+	doNotImplement
+}
+
+// ExtensionType encapsulates an ExtensionDescriptor with a concrete
+// Go implementation. The nested field descriptor must be for a extension field.
+//
+// While a normal field is a member of the parent message that it is declared
+// within (see Descriptor.Parent), an extension field is a member of some other
+// target message (see ExtensionDescriptor.Extendee) and may have no
+// relationship with the parent. However, the full name of an extension field is
+// relative to the parent that it is declared within.
+//
+// For example:
+//	syntax = "proto2";
+//	package example;
+//	message FooMessage {
+//		extensions 100 to max;
+//	}
+//	message BarMessage {
+//		extends FooMessage { optional BarMessage bar_field = 100; }
+//	}
+//
+// Field "bar_field" is an extension of FooMessage, but its full name is
+// "example.BarMessage.bar_field" instead of "example.FooMessage.bar_field".
+type ExtensionType interface {
+	// New returns a new value for the field.
+	// For scalars, this returns the default value in native Go form.
+	New() Value
+
+	// Zero returns a new value for the field.
+	// For scalars, this returns the default value in native Go form.
+	// For composite types, this returns an empty, read-only message, list, or map.
+	Zero() Value
+
+	// TypeDescriptor returns the extension type descriptor.
+	TypeDescriptor() ExtensionTypeDescriptor
+
+	// ValueOf wraps the input and returns it as a Value.
+	// ValueOf panics if the input value is invalid or not the appropriate type.
+	//
+	// ValueOf is more extensive than protoreflect.ValueOf for a given field's
+	// value as it has more type information available.
+	ValueOf(interface{}) Value
+
+	// InterfaceOf completely unwraps the Value to the underlying Go type.
+	// InterfaceOf panics if the input is nil or does not represent the
+	// appropriate underlying Go type. For composite types, it panics if the
+	// value is not mutable.
+	//
+	// InterfaceOf is able to unwrap the Value further than Value.Interface
+	// as it has more type information available.
+	InterfaceOf(Value) interface{}
+
+	// IsValidValue reports whether the Value is valid to assign to the field.
+	IsValidValue(Value) bool
+
+	// IsValidInterface reports whether the input is valid to assign to the field.
+	IsValidInterface(interface{}) bool
+}
+
+// EnumDescriptor describes an enum and
+// corresponds with the google.protobuf.EnumDescriptorProto message.
+//
+// Nested declarations:
+// EnumValueDescriptor.
+type EnumDescriptor interface {
+	Descriptor
+
+	// Values is a list of nested enum value declarations.
+	Values() EnumValueDescriptors
+
+	// ReservedNames is a list of reserved enum names.
+	ReservedNames() Names
+	// ReservedRanges is a list of reserved ranges of enum numbers.
+	ReservedRanges() EnumRanges
+
+	isEnumDescriptor
+}
+type isEnumDescriptor interface{ ProtoType(EnumDescriptor) }
+
+// EnumType encapsulates an EnumDescriptor with a concrete Go implementation.
+type EnumType interface {
+	// New returns an instance of this enum type with its value set to n.
+	New(n EnumNumber) Enum
+
+	// Descriptor returns the enum descriptor.
+	//
+	// Invariant: t.Descriptor() == t.New(0).Descriptor()
+	Descriptor() EnumDescriptor
+}
+
+// EnumDescriptors is a list of enum declarations.
+type EnumDescriptors interface {
+	// Len reports the number of enum types.
+	Len() int
+	// Get returns the ith EnumDescriptor. It panics if out of bounds.
+	Get(i int) EnumDescriptor
+	// ByName returns the EnumDescriptor for an enum named s.
+	// It returns nil if not found.
+	ByName(s Name) EnumDescriptor
+
+	doNotImplement
+}
+
+// EnumValueDescriptor describes an enum value and
+// corresponds with the google.protobuf.EnumValueDescriptorProto message.
+//
+// All other proto declarations are in the namespace of the parent.
+// However, enum values do not follow this rule and are within the namespace
+// of the parent's parent (i.e., they are a sibling of the containing enum).
+// Thus, a value named "FOO_VALUE" declared within an enum uniquely identified
+// as "proto.package.MyEnum" has a full name of "proto.package.FOO_VALUE".
+type EnumValueDescriptor interface {
+	Descriptor
+
+	// Number returns the enum value as an integer.
+	Number() EnumNumber
+
+	isEnumValueDescriptor
+}
+type isEnumValueDescriptor interface{ ProtoType(EnumValueDescriptor) }
+
+// EnumValueDescriptors is a list of enum value declarations.
+type EnumValueDescriptors interface {
+	// Len reports the number of enum values.
+	Len() int
+	// Get returns the ith EnumValueDescriptor. It panics if out of bounds.
+	Get(i int) EnumValueDescriptor
+	// ByName returns the EnumValueDescriptor for the enum value named s.
+	// It returns nil if not found.
+	ByName(s Name) EnumValueDescriptor
+	// ByNumber returns the EnumValueDescriptor for the enum value numbered n.
+	// If multiple have the same number, the first one defined is returned
+	// It returns nil if not found.
+	ByNumber(n EnumNumber) EnumValueDescriptor
+
+	doNotImplement
+}
+
+// ServiceDescriptor describes a service and
+// corresponds with the google.protobuf.ServiceDescriptorProto message.
+//
+// Nested declarations: MethodDescriptor.
+type ServiceDescriptor interface {
+	Descriptor
+
+	// Methods is a list of nested message declarations.
+	Methods() MethodDescriptors
+
+	isServiceDescriptor
+}
+type isServiceDescriptor interface{ ProtoType(ServiceDescriptor) }
+
+// ServiceDescriptors is a list of service declarations.
+type ServiceDescriptors interface {
+	// Len reports the number of services.
+	Len() int
+	// Get returns the ith ServiceDescriptor. It panics if out of bounds.
+	Get(i int) ServiceDescriptor
+	// ByName returns the ServiceDescriptor for a service named s.
+	// It returns nil if not found.
+	ByName(s Name) ServiceDescriptor
+
+	doNotImplement
+}
+
+// MethodDescriptor describes a method and
+// corresponds with the google.protobuf.MethodDescriptorProto message.
+type MethodDescriptor interface {
+	Descriptor
+
+	// Input is the input message descriptor.
+	Input() MessageDescriptor
+	// Output is the output message descriptor.
+	Output() MessageDescriptor
+	// IsStreamingClient reports whether the client streams multiple messages.
+	IsStreamingClient() bool
+	// IsStreamingServer reports whether the server streams multiple messages.
+	IsStreamingServer() bool
+
+	isMethodDescriptor
+}
+type isMethodDescriptor interface{ ProtoType(MethodDescriptor) }
+
+// MethodDescriptors is a list of method declarations.
+type MethodDescriptors interface {
+	// Len reports the number of methods.
+	Len() int
+	// Get returns the ith MethodDescriptor. It panics if out of bounds.
+	Get(i int) MethodDescriptor
+	// ByName returns the MethodDescriptor for a service method named s.
+	// It returns nil if not found.
+	ByName(s Name) MethodDescriptor
+
+	doNotImplement
+}