class A(BaseA, BaseB): a = fields.Field(mock.Mock(spec=Object))
class Inherit(Object): field = fields.Field(mock.Mock(spec=Object))
class BaseB(Object): base = fields.Field(mock.Mock(spec=Object)) base_b = fields.Field(mock.Mock(spec=Object))
class A(BaseA, BaseB): a = fields.Field(mock.Mock(spec=Object))
class Inherit(Object): field = fields.Field(mock.Mock(spec=Object))
class BaseB(Object): base = fields.Field(mock.Mock(spec=Object)) base_b = fields.Field(mock.Mock(spec=Object))