public function isUnionType( $qname )
	{
		$name = $qname instanceof QName ? "{$qname->prefix}:{$qname->localName}" : $qname;

		$type = $this->getType( $name );
		if ( ! $type ) return false;

		if ( isset( $type['restrictionType'] ) && $type['restrictionType'] == 'union' )
		{
			return true;
		}

		if ( ! isset( $type['parent'] ) ) return false;
		$name = $type['parent'];

		$type = $this->getType( $name );
		if ( ! $type ) return false;

		return isset( $type['restrictionType'] ) && $type['restrictionType'] == 'union';
	}