verifyObject doesn't correctly work on classes with classProvides

When for instance declaring a factory classProvides is handy at times:

>>> import zope.interface
>>> import zope.interface.verify
>>>
>>> class IFoo(zope.interface.Interface):
... def __call__(arg):
... pass
...
>>> class FooOkay(object):
... zope.interface.classProvides(IFoo)
... def __init__(self, arg):
... pass
...
>>> zope.interface.verify.verifyObject(IFoo, FooOkay)
True

That's was working.

The next case should raise an error, but doesn't. IFoo requires an arg to be passed which the following class doesn't implement:

>>> class FooVerifiedByNotLikeSpec(object):
... zope.interface.classProvides(IFoo)
...
>>> zope.interface.verify.verifyObject(IFoo, FooVerifiedByNotLikeSpec)
True

The next case should actually pass but doesn't.

>>> class FooBroken(object):
... zope.interface.classProvides(IFoo)
... def __init__(self, arg):
... pass
... def __call__(self):
... pass
...
>>> zope.interface.verify.verifyObject(IFoo, FooBroken)
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/Users/zagy/development/eggs/zope.interface-3.6.1-py2.7-macosx-10.6-x86_64.egg/zope/interface/verify.py", line 102, in verifyObject
    return _verify(iface, candidate, tentative, vtype='o')
  File "/Users/zagy/development/eggs/zope.interface-3.6.1-py2.7-macosx-10.6-x86_64.egg/zope/interface/verify.py", line 94, in _verify
    raise BrokenMethodImplementation(name, mess)
BrokenMethodImplementation: The implementation of __call__ violates its contract
        because implementation doesn't allow enough arguments.

>>>

Apparently verifyObject doesn't take any special care for classes which proivde an interface.