code: public void insertMention(@NonNull Mentionable mention) {
          if (mTokenizer == null) {
              return;
          }
  
          // Setup variables and ensure they are valid
          Editable text = getEditableText();
          int cursor = getSelectionStart();
          int start = mTokenizer.findTokenStart(text, cursor);
          int end = mTokenizer.findTokenEnd(text, cursor);
          if (start < 0 || start >= end || end > text.length()) {
              return;
          }
  
          insertMentionInternal(mention, text, start, end);
      }
docs: Inserts a mention into the token being considered currently.
  
  @param mention {@link Mentionable} to insert a span for