'Test an invocation of L{passed} with the given function, arguments, and
keyword arguments.
@param func: A function whose argspec will be inspected.
@type func: A callable.
@param args: The arguments which could be passed to C{func}.
@param kw: The keyword arguments which could be passed to C{func}.
@return: L{_passedSignature} or L{_passedArgSpec}\'s return value
@rtype: L{dict}'

def checkPassed(self, func, *args, **kw):

    if getattr(inspect, 'signature', None):
        return _passedSignature(inspect.signature(func), args, kw)
    else:
        return _passedArgSpec(inspect.getargspec(func), args, kw)
