R. David Murray added the comment:
It looks like the __slots__ declaration on Node was missed when the other slots
changes were made (by MvL in 3931f043b79a). Note that the Node base class
(xml.dom.Node) has a __slots__ declaration, but it was added after MvL's patch
(by Florent in 49c5511b23
New submission from Kevin Rocard:
Extracted from xml.dom.minidom:
~~~
Node(...):
...
ownerDocument = None
...
Element(Node):
__slots__=('ownerDocument', ...)
...
~~~
As Element declares an ownerDocument attribute in __slots__, Node's
ownerDocument attribute is hidden:
~~~
clas
