The result is a node set as defined by and will be accessed as a
single node, which may be
null
if the node set is empty.
The result is a node set as defined by and will be accessed as a
single node, which may be
null
if the node set is empty.
Document modification does not invalidate the node, but may mean that
the result node no longer corresponds to the current document. This
is a convenience that permits optimization since the implementation
can stop once any node in the in the resulting set has been found.
If there are more than one node in the actual result, the single
node returned might not be the first in document order.