Wrap and proxy method calls for builtin objects rather than error(?)

[bkabrda]

It could be useful to do something like the following to ensure all open() calls have a corresponding close(). Unfortunately it's a lot more cumbersome ATM due to inability to directly proxy for instances of builtin objects.

real_open = open
def wrap_open(*k, *kw):
  """ this could be a lambda one-liner even"""
  f = real_open(*k, **kw)
  flexmock(f).should_call('close').with_args().once
  return f

flexmock(__builtins__, open=wrap_open)

Original issue: has207/flexmock#82