public static LongBinding asLong(final ObservableValue<Number> source) {
        return Bindings.createLongBinding(() -> nonNullNumber(source.getValue()).longValue(), source);
    }
public static LongBinding asLong ( final ObservableValue < Number > source ) { return Bindings . createLongBinding ( ( ) -> nonNullNumber ( source . getValue ( ) ) . longValue ( ) , source ) ; }
Converts the given {@link javafx.beans.value.ObservableValue} of type {@link Number}
into an {@link javafx.beans.binding.LongBinding}.

This is done by the {@link Number#longValue()} method.

This method can be useful in situations where an operation or component only provides an observable value
of type number that you like to use to create calculation bindings.

It's the like a reverse-method of {@link javafx.beans.binding.LongBinding#asObject()}.

@param source the observable value that will be converted.
@return the LongBinding that holds the value of the source observable.