fixed python2.7 support

from contextlib import contextmanager

class suppress:

class suppress(object):

	"""

	A more advanced form of contextlib.suppress

	def __bool__(self):

		return self.exc_info[0] is not None

	__nonzero__ = __bool__ # python2.7 support

	@staticmethod

	def _append_args(args, extra):

		for arg in args:

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

#

import six

import unittest

from unittest import skipIf, skipUnless

from unittest_extra.generator import TestGeneratorMeta, test_generator

class TestCase(unittest.TestCase, metaclass=TestGeneratorMeta):

class TestCase(six.with_metaclass(TestGeneratorMeta, unittest.TestCase)):

	def assertKeysEqual(self, m1, m2, keys):

		for key in keys:

import tests

import importlib

import contextlib

from six.moves import reload_module

from django_utils_extra import network

		sys.modules = real_modules

class BackendMixin:

class BackendMixin(object):

	"""Causes different backends to be tested (if available, otherwise skips)"""

	backend = None

				.format(repr(self.backend), ', '.join(network.BACKENDS)))

		with temp_module_cache():

			for backend in network.BACKENDS:

				if backend == self.backend:

					continue

				sys.modules[backend] = None

			del sys.modules[self.backend]

			del sys.modules[network.__name__]

			try:

				importlib.import_module(self.backend)

			except (ImportError) as exc:

				self.skipTest(

					"the {0} backend is not available: {1}"

					.format(self.backend, exc))

			self.network = importlib.import_module(network.__name__)

			self.network = reload_module(network)

			self.Network = self.network.Network

class TestNetworkMixin:

class TestNetworkMixin(object):

	def test_addr(self):

		"""Test contains for implicit 32bit netmask ranges (single addresses)"""