A GroupIterator is an iterator that iterates over a sequence of groups.
The normal methods such as next() and current() always deliver the leading item
of the group. Additional methods are available to get the grouping key for the
current group (only applicable to group-by and group-adjacent), and to get all the
members of the current group.
Nested Class Summary
Nested classes/interfaces inherited from interface net.sf.saxon.om.SequenceIterator