def _add_service(self, name, addrinfo):
        if name not in self.services:
            self.services[name] = {}
        is_new = addrinfo not in self.services
        self.services[name][addrinfo] = time.time()
        if is_new:
            try:
                self.on_service_added(name, addrinfo)
            except Exception:
                self.logger.exception('error executing service add callback')
Print a tree of nodes.  This is like render_tree, except it prints
dataset/ETHPy150Open sccn/SNAP/src/rpyc/utils/registry.py/RegistryServer._add_service--crossover with--dataset/ETHPy150Open kayhayen/Nuitka/nuitka/build/inline_copy/lib/scons-2.3.2/SCons/Util.py/print_tree