code: public ListenableFuture<Void> nop() {
          checkThatDistributedStoreIsActive();
          KayVeeCommand.NOPCommand nopCommand = new KayVeeCommand.NOPCommand(getCommandId());
          return issueCommandToCluster(nopCommand);
      }
docs: Issue a {@link KayVeeCommand.NOPCommand}.
  This command will not modify the replicated storage's key-value state.
  
  @return future that will be triggered when the command is successfully
  <strong>committed</strong> to replicated storage or is <strong>known</strong>
  to have failed. This future <strong>may not</strong> be triggered. Callers
  are advised <strong>not</strong> to wait indefinitely, and instead, use
  timed waits.