protected GitHubService verifyRepository(String user,String repository){
  if (user == null)   throw new IllegalArgumentException("User cannot be null");
  if (user.length() == 0)   throw new IllegalArgumentException("User cannot be empty");
  if (repository == null)   throw new IllegalArgumentException("Repository cannot be null");
  if (repository.length() == 0)   throw new IllegalArgumentException("Repository cannot be empty");
  return this;
}

protected GitHubService verifyRepository ( String user , String repository ) { if ( user == null ) throw new IllegalArgumentException ( "User cannot be null" ) ; if ( user . length ( ) == 0 ) throw new IllegalArgumentException ( "User cannot be empty" ) ; if ( repository == null ) throw new IllegalArgumentException ( "Repository cannot be null" ) ; if ( repository . length ( ) == 0 ) throw new IllegalArgumentException ( "Repository cannot be empty" ) ; return this ; }
verify user and repository name
