<T extends EditorCustomElementRenderer>
  @Nullable Inlay<T> addBlockElement(int offset, boolean relatesToPrecedingText, boolean showAbove, int priority, @NotNull T renderer);
<T extends EditorCustomElementRenderer>
  @Nullable Inlay<T> addBlockElement(int offset, boolean relatesToPrecedingText, boolean showAbove, int priority, @NotNull T renderer)