class NestedNode(StandardSchema):
foo = fields.SelfReference()
foo_nested1 = fields.String()
foo_nested2 = fields.String()
foo_nested3 = fields.String()
foo_nested4 = fields.String()
foo_nested5 = fields.String()
foo_nested6 = fields.String()
foo_nested7 = fields.String()
foo_nested8 = fields.String()
foo_nested9 = fields.String()
foo_nested10 = fields.String()
foo_nested11 = fields.String()
foo_nested12 = fields.String()
foo_nested13 = fields.String()
foo_nested14 = fields.String()
foo_nested15 = fields.String()
foo_nested16 = fields.String()
foo_nested17 = fields.String()
foo_nested18 = fields.String()
foo_nested19 = fields.String()
foo_nested20 = fields.String()
foo_nested21 = fields.String()
foo_nested22 = fields.String()
foo_nested23 = fields.String()
foo_nested24 = fields.String()
foo_nested25 = fields.String()
foo_nested26 = fields.String()
foo_nested27 = fields.String()
foo_nested28 = fields.String()
foo_nested29 = fields.String()
foo_nested30 = fields.String()
foo_nested31 = fields.String()
foo_nested32 = fields.String()
foo_nested33 = fields.String()
foo_nested34 = fields.String()
foo_nested35 = fields.String()
foo_nested36 = fields.String()
foo_nested37 = fields.String()
foo_nested38 = fields.String()
foo_nested39 = fields.String()
foo_nested40 = fields.String()
foo_nested41 = fields.String()
foo_nested42 = fields.String()
class ABC(Schema):
a = fields.String()
abc = fields.SelfReference(whitelist=['a'], exclude=['a'])
class ABC(Schema):
a = fields.String()
abc = fields.SelfReference(exclude=['abc'])