code: private void updateLastModifiedAndChildCount(long id, long opTimeMs, long deltaChildCount) {
      try (LockResource lr = mInodeLockManager.lockUpdate(id)) {
        MutableInodeDirectory inode = mInodeStore.getMutable(id).get().asDirectory();
        boolean madeUpdate = false;
        if (inode.getLastModificationTimeMs() < opTimeMs) {
          inode.setLastModificationTimeMs(opTimeMs);
          madeUpdate = true;
        }
        if (deltaChildCount != 0) {
          inode.setChildCount(inode.getChildCount() + deltaChildCount);
          madeUpdate = true;
        }
        if (madeUpdate) {
          mInodeStore.writeInode(inode);
        }
      }
    }
docs: Updates the last modified time (LMT) for the indicated inode directory, and updates its child
  count.
  
  If the inode's LMT is already greater than the specified time, the inode's LMT will not be
  changed.
  
  @param id the inode to update
  @param opTimeMs the time of the operation that modified the inode
  @param deltaChildCount the change in inode directory child count