* @param walkedPath WalkedPath to evaluate against
* @return The data specified by this TransposePathElement, or null if it can't find anything.
*/
public Object objectEvaluate( WalkedPath walkedPath ) {
// Grap the data we need from however far up the tree we are supposed to go
PathStep pathStep = walkedPath.elementFromEnd( upLevel );
Object treeRef = pathStep.getTreeRef();
// Now walk down from that level using the subPathReader
if ( subPathReader == null ) {
return treeRef;
}