code: public Element prependElement(String tagName) {
          Element child = new Element(Tag.valueOf(tagName, NodeUtils.parser(this).settings()), baseUri());
          prependChild(child);
          return child;
      }
docs: Create a new element by tag name, and add it as the first child.
  
  @param tagName the name of the tag (e.g. {@code div}).
  @return the new element, to allow you to add content to it, e.g.:
  {@code parent.prependElement("h1").attr("id", "header").text("Welcome");}