static concat(var_args) {
    return SafeHtml.join(SafeHtml.EMPTY, Array.prototype.slice.call(arguments));
  }
Creates a new SafeHtml object by concatenating values.
@param {...(!SafeHtml.TextOrHtml_|
    !Array<!SafeHtml.TextOrHtml_>)} var_args Values to concatenate.
@return {!SafeHtml}
@deprecated Use `safevalues.concatHtmls` instead.