function offsetunset($key) {
		if (Base::instance()->visible($this,$key))
			unset($this->$key);
		else
			$this->clear($key);
	}
function offsetunset($key) {
		if (Base::instance()->visible($this,$key))
			unset($this->$key);
		else
			$this->clear($key);
	}
function offsetunset ( $ key ) { if ( Base :: instance ( ) -> visible ( $ this , $ key ) ) unset ( $ this -> $ key ) ; else $ this -> clear ( $ key ) ; }
Convenience method for removing property value
@return NULL
@param $key string
Convenience method for removing property value