@NotNull
  GroupNode addOrGetGroup(@NotNull UsageGroup group,
                          int ruleIndex,
                          @NotNull Consumer<? super UsageViewImpl.NodeChange> edtModelToSwingNodeChangesQueue) {
    synchronized (this) {
      return insertGroupNode(group, ruleIndex, edtModelToSwingNodeChangesQueue);
    }
  }
@NotNull
  GroupNode addOrGetGroup(@NotNull UsageGroup group,
                          int ruleIndex,
                          @NotNull Consumer<? super UsageViewImpl.NodeChange> edtModelToSwingNodeChangesQueue)