code: protected void append(Options options, CharSequence sequence) {
          TextSupport textSupport = this.textSupport;
          if (textSupport == null || isUnescapeVariable(options)) {
              options.append(sequence);
          } else {
              try {
                  textSupport.appendEscapedHtml(sequence.toString(),
                          options.getAppendable());
              } catch (IOException e) {
                  throw new MustacheException(MustacheProblem.RENDER_IO_ERROR, e);
              }
          }
      }
docs: Escape appended sequence if needed.
  
  @param options
  @param sequence
  @see TextSupport