code: private void performNextWrite() {
          Append append = getNextAppend();
          if (append == null) {
              return;
          }
          long traceId = LoggerHelpers.traceEnter(log, "storeAppend", append);
          Timer timer = new Timer();
          storeAppend(append)
                  .whenComplete((v, e) -> {
                      handleAppendResult(append, e, timer);
                      LoggerHelpers.traceLeave(log, "storeAppend", traceId, v, e);
                  })
                  .whenComplete((v, e) -> append.getData().release());
      }
docs: If there isn't already an append outstanding against the store, write a new one.
  Appends are opportunistically batched here. i.e. If many are waiting they are combined into a single append and
  that is written.