public function addRule( ADT_CSS_Rule $rule ){
		$got = $this->getRuleBySelector( $rule->selector );
		if( $got )
			foreach( $rule->getProperties() as $property )
				$got->setPropertyByKey( $property->getKey(), $property->getValue() );
		else{
			if( !preg_match( '/([a-z])|(#|\.[a-z])/i', $rule->getSelector() ) )
				throw new InvalidArgumentException( 'Invalid selector' );
			$this->rules[]	= $rule;
		}
	}