Generic method call using trigger()

gistfile1.php

<?php

public function findMemberById($id)
{
    $params = $this->getEventManager()->prepareArgs(compact(func_get_args()));
    $result = $this->getEventManager()->trigger(__FUNCTION__ . '.pre', $this, $params, function ($listenerOutput) {
    	return ($listenerOutput != null);
    });
    extract((array)$params);
	
    if ($result->stopped()) {
        return $result->last();
    }

    // Expensive calls here

    $params['__RESULT__'] = $calculatedResult;
    $this->getEventManager()->trigger(__FUNCTION__ . '.post', $this, $params);

    return $calculatedResult;
}