def append(self, name, attrs=None, data=None):
elem = self.__class__(name, attrs, data, parent=self, index=len(self._children))<EOL>self._children.append(elem)<EOL>return elem<EOL>
Called when the parser detects a start tag (child element) while in this node. Internally creates an
:class:`XmlElement` and adds it to the end of this node's children.

:param name: The tag name to add
:param attrs: Attributes for the new tag
:param data: CDATA for the new tag
:returns: The newly-created element
:rtype: :class:`XmlElement`