function jstLoadTemplateIfNotPresent(doc, name, loadHtmlFn, opt_target) {
  var section = domGetElementById(doc, name);
  if (section) {
    return section;
  }
  // Load any necessary HTML and try again.
  jstLoadTemplate_(doc, loadHtmlFn(), opt_target || STRING_jsts);
  var section = domGetElementById(doc, name);
  if (!section) {
    log("Error: jstGetTemplate was provided with opt_loadHtmlFn, " +
	"but that function did not provide the id '" + name + "'.");
  }
  return /** @type Element */(section);
}
If an element with id 'name' is not present in the document, call loadHtmlFn
and insert the result into the DOM.

@param {Document} doc
@param {string} name
@param {Function} loadHtmlFn A function that returns HTML to be inserted
into the DOM.
@param {string} opt_target The id of a DOM object under which to attach the
  HTML once it's inserted.  An object with this id is created if it does not
  exist.
@return {Element} The node whose id is 'name'