public function append(array $alias, $mode = LibBaseTemplateFilter::MODE_READ)
    {
        if ($mode & LibBaseTemplateFilter::MODE_READ) {
            $this->_alias_read = array_merge($this->_alias_read, $alias);
        }

        if ($mode & LibBaseTemplateFilter::MODE_WRITE) {
            $this->_alias_write = array_merge($this->_alias_write, $alias);
        }

        return $this;
    }