public function isOptionKeyValid($key)
    {
        self::parseValidKeys();

        if (isset(self::$validOptions[$key])) {
            return true;
        }

        return false;
    }
public function isOptionKeyValid($key)
    {
        self::parseValidKeys();

        if (isset(self::$validOptions[$key])) {
            return true;
        }

        return false;
    }
public function isOptionKeyValid ( $ key ) { self :: parseValidKeys ( ) ; if ( isset ( self :: $ validOptions [ $ key ] ) ) { return true ; } return false ; }
Checks if the given option key is valid for ZMQ.

@param mixed $key

@return boolean
Checks if the given option key is valid for ZMQ .