Appends newChild as the node's last child.
If newChild is the child of another node, it is reparented to this node. If newChild is a child of this node, then its position in the list of children is changed.
If newChild is a QDomDocumentFragment, then the children of the fragment are removed from the fragment and appended.
Calling this function on a null node(created, for example, with the default constructor) does nothing.
The DOM specification disallow inserting attribute nodes, but due to historical reasons QDom accept them nevertheless.