Called when a column is removed from a class, with the arguments
(cls, connection, column_name, so_column_obj, post_funcs).
Like AddColumnSignal this is called after the action has been
performed, and is called for subclassing (when a column is
implicitly removed by setting it to None).
The DeleteColumnSignal class is accessible via the
post_funcs are called with (cls, so_column_obj)
__sizeof__() -> int
size of object in memory, in bytes
Abstract classes can override this to customize issubclass().
This is invoked early on by abc.ABCMeta.__subclasscheck__().
It should return True, False or NotImplemented. If it returns
NotImplemented, the normal algorithm is used. Otherwise, it
overrides the normal algorithm (and the outcome is cached).
x.__init__(...) initializes x; see help(type(x)) for signature
for more information.