SetXY = function (items, x, y, stepX, stepY, index, direction)
{
    if (y === undefined || y === null) { y = x; }

    PropertyValueSet(items, 'x', x, stepX, index, direction);

    return PropertyValueSet(items, 'y', y, stepY, index, direction);
}
Takes an array of Game Objects, or any objects that have the public properties `x` and `y`
and then sets them to the given values.

The optional `stepX` and `stepY` properties are applied incrementally, multiplied by each item in the array.

To use this with a Group: `SetXY(group.getChildren(), x, y, stepX, stepY)`

@function Phaser.Actions.SetXY
@since 3.0.0

@generic {Phaser.GameObjects.GameObject[]} G - [items,$return]

@param {(array|Phaser.GameObjects.GameObject[])} items - The array of items to be updated by this action.
@param {number} x - The amount to set the `x` property to.
@param {number} [y=x] - The amount to set the `y` property to. If `undefined` or `null` it uses the `x` value.
@param {number} [stepX=0] - This is added to the `x` amount, multiplied by the iteration counter.
@param {number} [stepY=0] - This is added to the `y` amount, multiplied by the iteration counter.
@param {number} [index=0] - An optional offset to start searching from within the items array.
@param {number} [direction=1] - The direction to iterate through the array. 1 is from beginning to end, -1 from end to beginning.

@return {(array|Phaser.GameObjects.GameObject[])} The array of objects that were passed to this Action.