code: def get(self, key, default=None):
          
          if key not in self._ports:
              self._ports[key] = self._port_template(key)
          return self._vals.get(key, default)
docs: >>> inputs = InputPorts({"one": 1})
          >>> "one" in inputs._ports
          True
          >>> "one" in inputs._vals
          True
          >>> inputs.get("one", 2) == 1
          True
          >>> inputs.get("two", 2) == 2
          True
          >>> "two" in inputs._ports
          True
          >>> "two" in inputs._vals
          False