original_string: public function changeUsername()
      {
          if ($this->validate()) {
              $username = $this->user->createUsername($this->username);
              if (!$username) {
                  return false;
              }
              return $username->save();
          }
          return false;
      }
code: public function changeUsername()
      {
          if ($this->validate()) {
              $username = $this->user->createUsername($this->username);
              if (!$username) {
                  return false;
              }
              return $username->save();
          }
          return false;
      }
code_tokens: public function changeUsername ( ) { if ( $ this -> validate ( ) ) { $ username = $ this -> user -> createUsername ( $ this -> username ) ; if ( ! $ username ) { return false ; } return $ username -> save ( ) ; } return false ; }
docstring: Change username.
  @return bool
docstring_tokens: Change username .