code: private void incrementLastAppliedIndex(long expectedNewIndex) {
          checkArgument(expectedNewIndex > 0, "expectedNewIndex must be positive: given:%s", expectedNewIndex);
          checkArgument(expectedNewIndex == lastAppliedIndex + 1, "lastAppliedIndex not increasing monotonically: lastAppliedIndex:%s expectedNewIndex:%s", lastAppliedIndex, expectedNewIndex);
  
          lastAppliedIndex++;
      }
docs: Increment by one the value of {@link LocalStore#lastAppliedIndex}.
  
  @param expectedNewIndex new value of {@code lastAppliedIndex} after the increment
  @throws IllegalArgumentException if {@code lastAppliedIndex} is
  not positive or {@code lastAppliedIndex + 1 != expectedNewIndex}