public function appendChild( $child = null /* .. AbstractElement $element .. */ ) {
		$arg_list = func_get_args();

		foreach( $arg_list as $arg ) {
			if( $arg instanceof AbstractElement ) {
				$inject = $arg;
			} elseif( is_scalar($arg) ) {
				$inject = new Text($arg);
			} else {
				throw new \InvalidArgumentException;
			}

			$inject->_setParent($this);
			$this->childElements[] = $inject;
		}

		return $this;
	}