docs: static Method getGaugeMethod(Registry registry, Id id, Object obj, String method) {
      try {
        final Method m = Utils.getMethod(obj.getClass(), method);
        try {
          // Make sure we can cast the response to a Number
          final Number n = (Number) m.invoke(obj);
          REGISTRY_LOGGER.debug(
              "registering gauge {}, using method [{}], with initial value {}", id, m, n);
          return m;
        } catch (Exception e) {
          final String msg = "exception thrown invoking method [" + m
              + "], skipping registration of gauge " + id;
          registry.propagate(msg, e);
        }
      } catch (NoSuchMethodException e) {
        final String mname = obj.getClass().getName() + "." + method;
        final String msg = "invalid method [" + mname + "], skipping registration of gauge " + id;
        registry.propagate(msg, e);
      }
      return null;
    }