/**
* Overrides the "StateMachine::initializeExecutionState" method,
* in order to support/emit the ON_EXECUTION_STARTED event.
*
* @param StatefulSubjectInterface $subject
*
* @return StateInterface
*/
protected function initializeExecutionState(StatefulSubjectInterface $subject)
{
$initial_state = parent::initializeExecutionState($subject);
$this->fireEvent(self::ON_EXECUTION_STARTED, $subject, $initial_state);
return $initial_state;
}
