diff --git a/vendor/github.com/mongodb/mongo-go-driver/x/mongo/driver/distinct.go b/vendor/github.com/mongodb/mongo-go-driver/x/mongo/driver/distinct.go
new file mode 100644
index 0000000..eed7390
--- /dev/null
+++ b/vendor/github.com/mongodb/mongo-go-driver/x/mongo/driver/distinct.go
@@ -0,0 +1,77 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// 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
+
+package driver
+
+import (
+	"context"
+	"github.com/mongodb/mongo-go-driver/mongo/options"
+	"github.com/mongodb/mongo-go-driver/x/bsonx"
+
+	"github.com/mongodb/mongo-go-driver/x/mongo/driver/session"
+	"github.com/mongodb/mongo-go-driver/x/mongo/driver/topology"
+	"github.com/mongodb/mongo-go-driver/x/mongo/driver/uuid"
+	"github.com/mongodb/mongo-go-driver/x/network/command"
+	"github.com/mongodb/mongo-go-driver/x/network/description"
+	"github.com/mongodb/mongo-go-driver/x/network/result"
+	"time"
+)
+
+// Distinct handles the full cycle dispatch and execution of a distinct command against the provided
+// topology.
+func Distinct(
+	ctx context.Context,
+	cmd command.Distinct,
+	topo *topology.Topology,
+	selector description.ServerSelector,
+	clientID uuid.UUID,
+	pool *session.Pool,
+	opts ...*options.DistinctOptions,
+) (result.Distinct, error) {
+
+	ss, err := topo.SelectServer(ctx, selector)
+	if err != nil {
+		return result.Distinct{}, err
+	}
+
+	desc := ss.Description()
+	conn, err := ss.Connection(ctx)
+	if err != nil {
+		return result.Distinct{}, err
+	}
+	defer conn.Close()
+
+	rp, err := getReadPrefBasedOnTransaction(cmd.ReadPref, cmd.Session)
+	if err != nil {
+		return result.Distinct{}, err
+	}
+	cmd.ReadPref = rp
+
+	// If no explicit session and deployment supports sessions, start implicit session.
+	if cmd.Session == nil && topo.SupportsSessions() {
+		cmd.Session, err = session.NewClientSession(pool, clientID, session.Implicit)
+		if err != nil {
+			return result.Distinct{}, err
+		}
+		defer cmd.Session.EndSession()
+	}
+
+	distinctOpts := options.MergeDistinctOptions(opts...)
+
+	if distinctOpts.MaxTime != nil {
+		cmd.Opts = append(cmd.Opts, bsonx.Elem{
+			"maxTimeMS", bsonx.Int64(int64(*distinctOpts.MaxTime / time.Millisecond)),
+		})
+	}
+	if distinctOpts.Collation != nil {
+		if desc.WireVersion.Max < 5 {
+			return result.Distinct{}, ErrCollation
+		}
+		cmd.Opts = append(cmd.Opts, bsonx.Elem{"collation", bsonx.Document(distinctOpts.Collation.ToDocument())})
+	}
+
+	return cmd.RoundTrip(ctx, desc, conn)
+}