code: protected void addBasicAuthHeader(HttpHeaders headers, String user, String password){
  		headers.add(HEADER_AUTHORIZATION, buildBasicAuthValue(user, password));
  	}
docs: Add HTTP Basic Auth header
  @param headers	the headers, it must not be a read-only one, if it is, use {@link #copy(HttpHeaders)} to make a writable copy first
  @param user			the user name, may be null or empty
  @param password		the password, may be null or empty