Locator that uses the provided org.w3c.dom.Node
as the source of text. This is useful when iterating a array of nodes from another locator and
being able to transform each found Node into another Locator.
Locators are one shot objects. A call to
getNodes() should return the same Nodes every time it is called. Even if the underlying
data source has changed (for example the WebTester page has changed) the
Locator MUST return the same data.