The new style of class creation, with the declaration of a parent class, created a unified object model in Python,
so that the type of an instantiated class is equal to its class. In Python 2.2-2.7, this is not the case for old-style classes.
In Python 3+ all classes are new-style classes.
However, since the behavior can differ from 2.2+ to 3+, explicitly inheriting from object
(if there is no better candidate) is recommended.
class MyClass():
pass
class MyClass(object):
pass