public function validateFieldName($field)
    {
        if (!$field || $field != lcfirst(preg_replace('/[^a-zA-Z]+/', '', $field))) {
            throw $this->getException(
                'The parameter isn\'t valid ("%s" given, expecting camelcase separated words)',
                [$field]
            );
        }

        if (in_array(strtolower($field), $this->getReservedKeywords())) {
            throw $this->getException('"%s" is a reserved word.', [$field]);
        }

        return $field;
    }