isContextDocumentNodeSet()
Determine, in the case of an expression whose data type is Value.NODESET,
whether all the nodes in the node-set are guaranteed to come from the same
document as the context node.
Determine, in the case of an expression whose data type is Value.NODESET,
whether all the nodes in the node-set are guaranteed to come from the same
document as the context node. Used for optimization.
Following copied from class: com.icl.saxon.expr.Expression
Parameters:
context - The context in which the expression is to be evaluated
Returns:
the value of the expression, evaluated in the current context. Note that
the result is not necessarily in document order; to get it into document order,
call sort() on the result.
Throws:
XPathException - when the expression does not return a nodeset.