Answer an iterator over all of the values of this path component when
evaluated with respect to the given node.
Parameters: node - The parent node to evaluate against An iterator over all of the objects that correspond to evaluatingthis path against the given node.
Answer the first value for this path expression against the given node.
Parameters: node - The parent node to evalauate against The first object that corresponds to evaluatingthis path against the given node, or null if there is no such value