code: ClusterState commit() {
      // Apply the configuration to the local server state.
      context.transition(member.type());
      if (!configuration.members().contains(member) && leaveFuture != null) {
        leaveFuture.complete(null);
      }
  
      // If the local stored configuration is older than the committed configuration, overwrite it.
      if (context.getMetaStore().loadConfiguration().index() < configuration.index()) {
        context.getMetaStore().storeConfiguration(configuration);
      }
      return this;
    }
docs: Commit the current configuration to disk.
  
  @return The cluster state.