Creates a new javafx.beans.binding.BooleanBinding that contains the element of an javafx.collections.ObservableList at the specified position. The BooleanBinding will hold false, if the index points behind the ObservableList.

Parameters:

op the ObservableList

index the position in the List

Returns: the new BooleanBinding

Exceptions:

NullPointerException if the ObservableList is null

IllegalArgumentException if (@code index < 0}

Since: JavaFX 2.1

`NullPointerException`		if the `ObservableList` is `null`
`IllegalArgumentException`		if (@code index < 0}