'Modify the fields after data were fetched from DB.
It uses the fields_need_translation dict with structure:
\'field_name_in_object\': \'field_name_in_db\'
:param db_obj: model fetched from database
:return: modified dict of DB values'

@classmethod
def modify_fields_from_db(cls, db_obj):

    potential_fields = (list(cls.fields.keys()) + list(cls.fields_need_translation.values()))
    result = {field: db_obj[field] for field in potential_fields if (db_obj.get(field) is not None)}
    for (field, field_db) in cls.fields_need_translation.items():
        if (field_db in result):
            result[field] = result.pop(field_db)
    return result
