public function createField($dbQuery, $entity, $param = null, $identifier = null)
    {
        if (class_exists($this->fieldClass)) {
            $this->field = new $this->fieldClass($dbQuery, $entity, $param, $identifier);
        } else {
            e('Class (##) not found', E_SAMSON_CORE_ERROR, $this->fieldClass);
        }
        return $this;
    }