private static ColumnInfo<UsageNode, UsageNode> @NotNull [] cols(int cols) {
      ColumnInfo<UsageNode, UsageNode> o = new ColumnInfo<>("") {
        @Nullable
        @Override
        public UsageNode valueOf(UsageNode node) {
          return node;
        }
      };
      List<ColumnInfo<UsageNode, UsageNode>> list = Collections.nCopies(cols, o);
      return list.toArray(ColumnInfo.emptyArray());
    }
private static ColumnInfo<UsageNode, UsageNode> @NotNull [] cols(int cols)