/**
   * Advanced check of task parameters.
   */
  protected function checkParameters($arguments = array(), $options = array())
  {
    // check parent parameters
    parent::checkParameters($arguments, $options);

    return true;
  }
 /**
  * Advanced check of task parameters.
  */
 protected function checkParameters($arguments = array(), $options = array())
 {
     // check parent parameters
     parent::checkParameters($arguments, $options);
     // Stupid test
     if ($this->args['arg_1'] != 'arg_1_value') {
         throw new InvalidArgumentException('The value for argument 1 is not valid ! Check the help of the task.');
     }
     return true;
 }