Creates a new javafx.beans.binding.BooleanBinding that holds true if a given javafx.collections.ObservableMap is not empty.

Parameters:

op		the ObservableMap
<K>		type of the key elements of the Map
<V>		type of the value elements of the Map

Returns:  the new BooleanBinding

Exceptions:

NullPointerException

if the ObservableMap is null

Since:  JavaFX 8.0