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: unix.go
    path of file: ./repos/moby/vendor/google.golang.org/grpc/internal/resolver/unix
    
    the code of the file until where you have to start completion: /*
 *
 * Copyright 2020 gRPC authors.
 *
 * 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 i
    
func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) {
	if target.URL.Host != "" {
		return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.URL.Host)
	}

	// gRPC was parsing the dial target manually before PR #4817, and we
	// switched to using url.Parse() in that PR. To avoid breaking existing
	// resolver implementations we ended up stripping the leading "/" from the
	// endpoint. This obviously does not work for the "unix" scheme. Hence we
	// end up using the parsed URL instead.
	endpoint := target.URL.Path
	if endpoint == "" {
		endpoint = target.URL.Opaque
	}
	addr := resolver.Address{Addr: endpoint}
	if b.scheme == unixAbstractScheme {
		// We can not prepend \0 as c++ gRPC does, as in Golang '@' is used to signify we do
		// not want trailing \0 in address.
		addr.Addr = "@" + addr.Addr
	}
	cc.UpdateState(resolver.State{Addresses: []resolver.Address{networktype.Set(addr, "unix")}})
	return &nopResolver{}, nil
}