function fliplr4d( x ) {
	var out;
	var i;

	out = [];
	for ( i = 0; i < x.length; i++ ) {
		out.push( fliplr3d( x[ i ] ) );
	}
	return out;
}
Reverses the order of elements along the last dimension of a four-dimensional nested input array.

## Notes

-   The function does **not** perform a deep copy of nested array elements.

@param {ArrayLikeObject<ArrayLikeObject<ArrayLikeObject<Collection>>>} x - nested input array
@returns {Array<Array<Array<Collection>>>} output array

@example
var x = [ [ [ [ 1, 2 ], [ 3, 4 ], [ 5, 6 ] ] ] ];

var out = fliplr4d( x );
// returns [ [ [ [ 2, 1 ], [ 4, 3 ], [ 6, 5 ] ] ] ]