function createHtmlText(tokens) {
  var htmlText = '';

  tokens.forEach(function(t) {
    var text = escapeHTML(t.value || t.matched || t.normal);
    var match = t.match || t.matched;

    if (match) {
      htmlText += '<b class="' + SearchPad.RESULT_HIGHLIGHT_CLASS + '">' + text + '</b>';
    } else {
      htmlText += text;
    }
  });

  return htmlText !== '' ? htmlText : null;
}
Create internal HTML markup from result tokens.
Caters for highlighting pattern matched tokens.

@param {Token[]} tokens

@return {string|null}