opcode is followed by code to create setstate's argument, and then a
BUILD opcode to apply __setstate__ to that argument.
- There are lots of special cases here. The argtuple can be None, in
- which case callable.__basicnew__() is called instead to produce the
- object to be pushed on the stack. This appears to be a trick unique
- to ExtensionClasses, and is deprecated regardless.
-
If type(callable) is not ClassType, REDUCE complains unless the
callable has been registered with the copy_reg module's
safe_constructors dict, or the callable has a magic