/**
  *
  * @param string $command
  */
 public function __construct($command, $operation)
 {
     parent::__construct('Operation "' . $operation . '" not found for command "' . $command . '".');
 }
 /**
  *
  * @param string $command
  */
 public function __construct($command)
 {
     parent::__construct('Command "' . $command . '" not found.');
 }