def __init__(self, groups=None):
        super(GroupedRequirements, self).__init__(NamedRequirements)
        self.groups = groups or self.default_groups
        self.filename = None
        self.create_default_groups()
def _ignoring_sigint(self):
        with self._ignore_sigint_lock:
            self._check_sigint_gate_is_correct()
            self._threads_ignoring_sigint += 1
        try:
            yield
        finally:
            with self._ignore_sigint_lock:
                self._threads_ignoring_sigint -= 1
                self._check_sigint_gate_is_correct()