original_string: public static function getInstance(HttpClient $transport = null)
      {
          if (is_null(self::$client)) {
              self::$client = new self();
          
              if (! is_null($transport)) {
                  self::$client->setTransport($transport);
              }
          }
          
          return self::$client;
      }
code: public static function getInstance(HttpClient $transport = null)
      {
          if (is_null(self::$client)) {
              self::$client = new self();
          
              if (! is_null($transport)) {
                  self::$client->setTransport($transport);
              }
          }
          
          return self::$client;
      }
code_tokens: public static function getInstance ( HttpClient $ transport = null ) { if ( is_null ( self :: $ client ) ) { self :: $ client = new self ( ) ; if ( ! is_null ( $ transport ) ) { self :: $ client -> setTransport ( $ transport ) ; } } return self :: $ client ; }
docstring: Return a singleton instance of the class
  @param GuzzleHttp\Client $transport
  @return Arrowsphere\Client\xAC
docstring_tokens: Return a singleton instance of the class