'assert that the mock was called exactly once and with the specified
arguments.'

def assert_called_once_with(_mock_self, *args, **kwargs):

    self = _mock_self
    if (not (self.call_count == 1)):
        msg = ("Expected    '%s'    to    be    called    once.    Called    %s    times." % ((self._mock_name or 'mock'), self.call_count))
        raise AssertionError(msg)
    return self.assert_called_with(*args, **kwargs)
