original_string: private function call() {
  
          if(null === $this -> driver) {
              return trigger_error('Driver is not set. Set the driver with the setDriver() method', E_USER_ERROR);
          }
  
          if(null === $this -> driverInstance) {
          	$this -> driverInstance = new $this -> driver();
          }
  
          return $this -> driverInstance;
      }
code: private function call() {
  
          if(null === $this -> driver) {
              return trigger_error('Driver is not set. Set the driver with the setDriver() method', E_USER_ERROR);
          }
  
          if(null === $this -> driverInstance) {
          	$this -> driverInstance = new $this -> driver();
          }
  
          return $this -> driverInstance;
      }
code_tokens: private function call ( ) { if ( null === $ this -> driver ) { return trigger_error ( 'Driver is not set. Set the driver with the setDriver() method' , E_USER_ERROR ) ; } if ( null === $ this -> driverInstance ) { $ this -> driverInstance = new $ this -> driver ( ) ; } return $ this -> driverInstance ; }
docstring: Check if driver is set and returns it
  @return mixed
docstring_tokens: Check if driver is set and returns it