/// <inheritdoc />
 public virtual ElementCollection <TElement> ElementsOfType <TElement>() where TElement : Element
 {
     return(AllElements.ElementsOfType <TElement>());
 }
 /// <inheritdoc />
 public ElementCollection <TChildElement> ElementsOfType <TChildElement>() where TChildElement : Element
 {
     return(AllElements.ElementsOfType <TChildElement>());
 }