'Run all check_* methods.'

def __call__(self):

    if self.on:
        oldformatwarning = warnings.formatwarning
        warnings.formatwarning = self.formatwarning
        try:
            for name in dir(self):
                if name.startswith('check_'):
                    method = getattr(self, name)
                    if (method and hasattr(method, '__call__')):
                        method()
        finally:
            warnings.formatwarning = oldformatwarning
