Composition of data

>>> from woger import BaseData
>>>
>>> class A(BaseData):
...     xml = lambda data: 'xml'
>>>
>>> class B(BaseData):
...     json = lambda data: 'convert {} to json'.format(data.xml)
>>>
>>> class C(A, B):
...     all = lambda data: (data.xml, data.json)
>>>
>>> data = C()
>>> print(data.xml, data.json, data.all, sep='\n')
xml
convert xml to json
('xml', 'convert xml to json')