VOL-4337: Code upgrade for 3/2020 G.988 support and remaining Extended Message Set support

Change-Id: I6c5e1a167216ad9b51e9da89460e9909465ae1bc
diff --git a/meframe/me_avc.go b/meframe/me_avc.go
new file mode 100644
index 0000000..e91339f
--- /dev/null
+++ b/meframe/me_avc.go
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2018 - present.  Boling Consulting Solutions (bcsw.net)
+ * Copyright 2020-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package meframe
+
+import (
+	"errors"
+	"fmt"
+	"github.com/google/gopacket"
+	. "github.com/opencord/omci-lib-go"
+	me "github.com/opencord/omci-lib-go/generated"
+)
+
+func AttributeValueChangeFrame(m *me.ManagedEntity, opt options) (gopacket.SerializableLayer, error) {
+	if opt.frameFormat == ExtendedIdent {
+		return nil, errors.New("extended message set for this message type is not supported")
+	}
+	mask, err := checkAttributeMask(m, opt.attributeMask)
+	if err != nil {
+		return nil, err
+	}
+	// Common for all MEs
+	meLayer := &AttributeValueChangeMsg{
+		MeBasePacket: MeBasePacket{
+			EntityClass:    m.GetClassID(),
+			EntityInstance: m.GetEntityID(),
+			Extended:       opt.frameFormat == ExtendedIdent,
+		},
+		AttributeMask: 0,
+		Attributes:    make(me.AttributeValueMap),
+	}
+	// Get payload space available
+	maxPayload := maxPacketAvailable(m, opt)
+	payloadAvailable := int(maxPayload) - 2 // Less attribute mask
+
+	// TODO: Lots of work to do
+
+	fmt.Println(mask, maxPayload, payloadAvailable)
+	return meLayer, errors.New("todo: Not implemented")
+}