public static void updateLastUnchangedContent(@NotNull VirtualFile file) {
    if (isTouched(file)) {
      return;
    }

    Long lastTs = getLastSavedStamp(file);
    final long stamp = file.getTimeStamp();
    if (lastTs != null && stamp == lastTs) {
      return;
    }

    Integer oldContentId = getSavedContentId(file);
    if (oldContentId != null && oldContentId > 0) {
      if (LOG.isDebugEnabled()) {
        LOG.debug("releasing content for " + file + ", id = " + oldContentId);
      }
      getFS().releaseContent(oldContentId);
    }

    saveContentReference(file, getFS().acquireContent(file));
    markTouched(file);
  }
public static void updateLastUnchangedContent(@NotNull VirtualFile file)