__init__ method is a generator
Used when the special class method __init__() is turned into a generator by a yield statement in its body.
This message belongs to the basic checker.
The __init__() method is required to return nothing. Python 2.7 and 3.x raises:
TypeError: __init__() should return None
when __init__() is called and executes a yield statement. PyLint reports this error without depending on the actual invocation.