StringMap<String> modified = annotationLogic.stripKeys(
destDoc, pos, cursorBias, ContentType.RICH_TEXT, builder);
// parse the tokens and apply ops
RichTextMutationBuilder mutationBuilder = new RichTextMutationBuilder(modified);
ReadableStringSet affectedKeys =
mutationBuilder.applyMutations(tokenizer, builder, destDoc, insertAt.getContainer());
// close annotations and finish
annotationLogic.unstripKeys(builder, modified.keySet(), affectedKeys);
builder.finish();