private Long handleToId(Object handle) {
        if (handle instanceof Long) {
            return (Long) handle;
        } else {
            throw new IllegalArgumentException("Expected handle to be a Long, but was: " +
                    handle.getClass().getCanonicalName());
        }
    }
private Long handleToId ( Object handle ) { if ( handle instanceof Long ) { return ( Long ) handle ; } else { throw new IllegalArgumentException ( "Expected handle to be a Long, but was: " + handle . getClass ( ) . getCanonicalName ( ) ) ; } }
Converts an opaque handle into a long ID. If the handle is not a Long, this will throw an
{@link java.lang.IllegalArgumentException}.

@param handle The handle to convert to an ID.
@return The ID.