More options around `exclude_if_none`

[venkat-raman-wday]

As noted in the document, the exclude_if_none is based off of Falsey-ness. While this might apply to most property types, it also doesn't apply in certain conditions to certain properties. For example, for an IntegerProperty, setting exclude_if_none=True doesn't work for cases where default=0 which is a valid value for this property and ends up being wrong. When generating a JSON based off of default values and validating against a schema, these cases make a big difference. There probably are other such scenarios. Any workarounds for this?

[venkat-raman-wday]

Well, I found a work around by overriding to_json() and checking the values of the keys in _obj's value. Any suggestions is welcome. I'd also like to know if there are private attributes where meta information for the attributes is stored so that I end up checking attributes for only certain property types.