Returns the dependencies of a binding in an unmodifiable javafx.collections.ObservableList. The implementation is optional. The main purpose of this method is to support developers during development. It allows to explore and monitor dependencies of a binding during runtime.

Because this method should not be used in production code, it is recommended to implement this functionality as sparse as possible. For example if the dependencies do not change, each call can generate a new ObservableList, avoiding the necessity to store the result.

Returns:  an unmodifiable ObservableList of the dependencies