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: data.go
    path of file: ./repos/hugo/tpl/data
    
    the code of the file until where you have to start completion: // Copyright 2017 The Hugo Authors. All rights reserved.
//
// 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 
    
func (ns *Namespace) GetCSV(sep string, args ...any) (d [][]string, err error) {
	hugo.Deprecate("data.GetCSV", "use resources.Get or resources.GetRemote with transform.Unmarshal.", "v0.123.0")

	url, headers := toURLAndHeaders(args)
	cache := ns.cacheGetCSV

	unmarshal := func(b []byte) (bool, error) {
		if d, err = parseCSV(b, sep); err != nil {
			err = fmt.Errorf("failed to parse CSV file %s: %w", url, err)

			return true, err
		}

		return false, nil
	}

	var req *http.Request
	req, err = http.NewRequest("GET", url, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to create request for getCSV for resource %s: %w", url, err)
	}

	// Add custom user headers.
	addUserProvidedHeaders(headers, req)
	addDefaultHeaders(req, "text/csv", "text/plain")

	err = ns.getResource(cache, unmarshal, req)
	if err != nil {
		if security.IsAccessDenied(err) {
			return nil, err
		}
		ns.deps.Log.Erroridf(constants.ErrRemoteGetCSV, "Failed to get CSV resource %q: %s", url, err)
		return nil, nil
	}

	return
}