public function Reset( $options = null ){
		$this->rules = array();
		self::$imports = array();
		self::$has_extends = false;
		self::$imports = array();
		self::$contentsMap = array();

		$this->env = new Less_Environment($options);
		$this->env->Init();

		//set new options
		if( is_array($options) ){
			$this->SetOptions(Less_Parser::$default_options);
			$this->SetOptions($options);
		}
	}