has_optional_field implementation may lead to unexpected results

[xavierfigueroav]

has_optional_field(field) verifies whether the value of field is not None. But, some attributes are sometimes initialized as some default/empty object, like an empty list. In that example, has_optional_field(field) will always return True, even if the list is empty (when I think it should return False because there is actually no information).

I suggest: return bool(field)

[b-thebest]

Can I work on this issue ?