code: function(query, option) {
    var result = new RegExp(query, "i").exec(option.textContent);
    if (result) {
      return option.textContent.replace(result[0], "<span class='selectr-match'>" + result[0] + "</span>");
    }
    return false;
  }
docs: Query matching for searches
  @param  {string} query
  @param  {HTMLOptionElement} option
  @return {bool}