public function get($key) {
        if (array_key_exists($key, $this->_fields)) {
            if (gettype($this->_fields['' . $key . '']) == 'object') {
                return $this->_fields['' . $key . '']->value;
            }
            else {
                return $this->_fields['' . $key . ''];
            }
        }
        else {
            throw new MissingEntityException('The field "' . $key . '" doesn\'t exist in ' . $this->_name);
        }
    }