Hello all! Please enlighten me about optional typecheck: 1) Will it be available in Python 2.5? 2) Will it support things like def f(a: int | float) 3) Will it support interface checking like def g(a: BookInterface) or even mix like def k(a: file | BookInterface) 4) Will it support things like def t(*args: T1 | T2, **kwds: T1 | T3)