Abstract Gets the position for the given Node/Group as dictated by either the left/top properties, or some other nominated pair, in the Node/Group's data.
This position is what the Absolute layout uses itself, and this method exposes the absolute position for subclasses that wish to make use
of the absolute backing.
Node/Group to get absolute position for.
Optional parameters: LayoutParametersConstructor parameters. May contain a custom locationFunction.
Base class for layouts that want to be backed with an absolute layout, ie. if for a given vertex there is positioning data available in the dataset, that positioning data should be used instead of the layout's computed position.