How to use the nose2.util function in nose2

def _find_tests_in_file(self, event, filename, full_path, top_level, module_name=None):
        log.debug("find in file %s (%s)", full_path, top_level)
        pattern = self.session.testFilePattern
        loader = event.loader
        evt = events.HandleFileEvent(
            loader, filename, full_path, pattern, top_level)
        result = self.session.hooks.handleFile(evt)
        if evt.extraTests:
            yield loader.suiteClass(evt.extraTests)

        if evt.handled:
            if result:
                yield result
            return

        if not util.valid_module_name(filename):
            # valid Python identifiers only
            return

        evt = events.MatchPathEvent(filename, full_path, pattern)
        result = self.session.hooks.matchPath(evt)
        if evt.handled:
            if not result:
                return
        elif not self._match_path(filename, full_path, pattern):
            return

        if module_name is None:
            module_name, package_path = util.name_from_path(full_path)
            util.ensure_importable(package_path)
        try:
            module = util.module_from_name(module_name)

def run(self):
        plugin_name = self.arguments[0]
        parent, plugin = util.object_from_name(plugin_name)
        if isinstance(plugin, types.ModuleType):
            # document all plugins in module
            module = plugin
            mod_name = module.__name__
            plugins = self.plugins(module)

        else:
            if 'module' in self.options:
                mod_name = self.options['module']
            else:
                mod_name = plugin_name[
                    0:plugin_name.index(plugin.__name__) - 1]
            plugins = [plugin]

        rst = ViewList()
        if mod_name:

def _inLayer(self, layer, test, method):
        meth = self._getBoundClassmethod(layer, method)
        if meth:
            if util.num_expected_args(meth) > 1:
                meth(test)
            else:
                meth()