An enumeration representing a nodeset that is an intersection of two other NodeSets.
There is currently no operator in XPath to create such an expression, but it is used
by the extension function difference(). The code is derived from the analagous UnionEnumeration,
an inner class of UnionExpression.
Determine whether there are more nodes to come.
(Note the term "Element" is used here in the sense of the standard Java Enumeration class,
it has nothing to do with XML elements).
Get the next node in sequence.
(Note the term "Element" is used here in the sense of the standard Java Enumeration class,
it has nothing to do with XML elements).
Determine whether the nodes returned by this enumeration are known to be peers, that is,
no node is a descendant or ancestor of another node. This significance of this property is
that if a peer enumeration is applied to each node in a set derived from another peer
enumeration, and if both enumerations are sorted, then the result is also sorted.