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: mongocrypt_kms_context.go
    path of file: ./repos/mongo-go-driver/x/mongo/driver/mongocrypt
    
    the code of the file until where you have to start completion: // Copyright (C) MongoDB, Inc. 2017-present.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may
// not 
    
func (kc *KmsContext) HostName() (string, error) {
	var hostname *C.char // out param for mongocrypt function to fill in hostname
	if ok := C.mongocrypt_kms_ctx_endpoint(kc.wrapped, &hostname); !ok {
		return "", kc.createErrorFromStatus()
	}
	return C.GoString(hostname), nil
}