You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: registry.go
    path of file: ./repos/docker-ce/components/cli/vendor/github.com/golang/protobuf/proto
    
    the code of the file until where you have to start completion: // Copyright 2019 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 proto

import (
	"bytes"
	"compress/gzip"
	"fmt"
	"io/ioutil"
	"reflect"
	"strings"
	"sync"

	"google.golang.org/protobuf/reflect/protodesc"
	"goog
    
func MessageType(s messageName) reflect.Type {
	if v, ok := messageTypeCache.Load(s); ok {
		return v.(reflect.Type)
	}

	// Derive the message type from the v2 registry.
	var t reflect.Type
	if mt, _ := protoregistry.GlobalTypes.FindMessageByName(protoreflect.FullName(s)); mt != nil {
		t = messageGoType(mt)
	}

	// If we could not get a concrete type, it is possible that it is a
	// pseudo-message for a map entry.
	if t == nil {
		d, _ := protoregistry.GlobalFiles.FindDescriptorByName(protoreflect.FullName(s))
		if md, _ := d.(protoreflect.MessageDescriptor); md != nil && md.IsMapEntry() {
			kt := goTypeForField(md.Fields().ByNumber(1))
			vt := goTypeForField(md.Fields().ByNumber(2))
			t = reflect.MapOf(kt, vt)
		}
	}

	// Locally cache the message type for the given name.
	if t != nil {
		v, _ := messageTypeCache.LoadOrStore(s, t)
		return v.(reflect.Type)
	}
	return nil
}