def install(self, version):
        """
        Check to see if the system-installed version of zope.interface matches
        the version requested.  If so, do nothing.  If not, skip the test (if
        the desired version is not installed, there is no way to test its
        behavior).  If the version of zope.interface cannot be determined
        (because pkg_resources is not installed), skip the test.
        """
        # Use an unrelated, but unreliable, route to try to determine what
        # version of zope.interface is installed on the system.  It's sort of
        # okay to use this unreliable scheme here, since if it fails it only
        # means we won't be able to run the tests.  Hopefully someone else
        # managed to run the tests somewhere else.
        try:
            import pkg_resources
        except ImportError as e:
            raise SkipTest(
                (e,) % "Cannot determine system version of zope.interface: %s")
        else:
            try:
                pkg = pkg_resources.get_distribution("zope.interface")
            except pkg_resources.DistributionNotFound as e:
                raise SkipTest(
                    "Cannot determine system version of zope.interface: %s" % (
                        e,))
            installed = pkg.version
            versionTuple = tuple(
                int(part) for part in installed.split('.')[:len(version)])
            if versionTuple == version:
                pass
            else:
                raise SkipTest("Mismatched system version of zope.interface")
dataset/ETHPy150Open twisted/twisted/twisted/test/test_twisted.py/RealZopeInterfaceTests.install/swapped operands of `%`