code: func (s *ChangesService) GetContent(changeID, revisionID, fileID string) (*string, *Response, error) {
  	u := fmt.Sprintf("changes/%s/revisions/%s/files/%s/content", changeID, revisionID, url.PathEscape(fileID))
  
  	req, err := s.client.NewRequest("GET", u, nil)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	v := new(string)
  	resp, err := s.client.Do(req, v)
  	if err != nil {
  		return nil, resp, err
  	}
  
  	return v, resp, err
  }
docs: // GetContent gets the content of a file from a certain revision.
  // The content is returned as base64 encoded string.
  // The HTTP response Content-Type is always text/plain, reflecting the base64 wrapping.
  // A Gerrit-specific X-FYI-Content-Type header is returned describing the server detected content type of the file.
  //
  // Gerrit API docs: https://gerrit-review.googlesource.com/Documentation/rest-api-changes.html#get-content