izzum\statemachine\persistence\Adapter::getState PHP Method

    public function getState(Identifier $identifier)
    {
        try {
            // execute a hook that should be implemented in a subclass.
            // the subclass could return STATE_UNKNOWN if it is not already
            // added to the storage backend or it might throw an exception warning the
            //end user that he should 'StateMachine::add' to the backend first
            $state = $this->processGetState($identifier);
            return $state;
        } catch (\Exception $e) {
            $e = Utils::wrapToStateMachineException($e, Exception::IO_FAILURE_GET);
            throw $e;
        }
    }