def METHOD_NAME(cls, *args, **kwargs):
    # Because pre_value is set to DefaultProperty, pre_value is automatically
    # interpreted to be a datatype when it's fetched by jsonobject.
    # This fails hard when the spec expects a string
    # and gets something else...like a date.
    doc = args[0]
    if 'pre_value' in doc:
        pre_value = doc['pre_value']
        data_type = doc.get('datatype')
        if data_type == 'string':
            doc['pre_value'] = str(pre_value)
    return super().METHOD_NAME(*args, **kwargs)