Called before an instance is created, with the class as the
sender. Called with the arguments (instance, kwargs, post_funcs).
There may be a connection argument. kwargs``may be usefully
modified. ``post_funcs is a list of callbacks, intended to have
functions appended to it, and are called with the arguments
The RowCreateSignal class is accessible via the
Note: this is not called when an instance is created from an
existing database row.
__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.