void appendHtml(String text, { NodeValidator validator, NodeTreeSanitizer treeSanitizer })

Parses the specified text as HTML and adds the resulting node after the last child of this element.

Source 

void appendHtml(String text,
    {NodeValidator validator, NodeTreeSanitizer treeSanitizer}) {
  this.insertAdjacentHtml('beforeend', text,
      validator: validator, treeSanitizer: treeSanitizer);
}