Why is DOMDocument derived from DOMNode ??

Hi All

A DOMDocument is just a container. So why is it derived from DOMNode?

For invoking DOMNode functions we should get the DocumentElement from the
Document and then invoke the functions we need.

I am trying to implement the DOMDocument interface and I'm quite puzzled as
to what should be the impl for getFirstChild, etc.


Thanks in Advance
Jaspreet