public function add($data)
    {
        $ea = (array) $data;
        foreach ($ea as $key => $value) {
            if (is_array($value)) {
                foreach ($value as $k => $v) {
                    if (is_null($v)) {
                        unset($value[$k]);
                    }
                }
                $value = array_values($value);
                $ea[$key] = $value;
            }
        }

        $this->_errors = $ea;
    }