public function addCondition($condition, $params = array(), $link = 'AND') {
        if (is_array($condition)) {
            $condition = $this->_fromArray($condition);
        }
        if (!$this->condition) { // if condition it's not already set then just add this one
            $this->condition = $condition;
            $this->setParams($params);
            return $this;
        }
        $this->condition = '(' . $this->condition . ') ' . $link . ' (' . $condition . ')';
        $this->setParams($params);
        return $this;
    }