code: public static ContainerMetrics get(final State containerState, final String applicationName,
        final String workerId) {
      return (ContainerMetrics) GOBBLIN_METRICS_REGISTRY.getOrDefault(name(workerId), new Callable<GobblinMetrics>() {
        @Override public GobblinMetrics call() throws Exception {
          return new ContainerMetrics(containerState, applicationName, workerId);
        }
      });
    }
docs: Get a {@link ContainerMetrics} instance given the {@link State} of a container, the name of the application the
  container belongs to, and the workerId of the container.
  
  @param containerState the {@link State} of the container
  @param applicationName a {@link String} representing the name of the application the container belongs to
  @return a {@link ContainerMetrics} instance