def __init__(self, field_required=False, default=None):
super(ObjectField, self).__init__(<EOL>field_type=str,<EOL>field_required=field_required,<EOL>default=default,<EOL>)<EOL>
unlike the normal Field class, you can't set any options or a type on this
Field, because it is a pickled object, so it can't be unique, it doesn't have
a size, etc.. Likewise, the field type is always str