3.1.5.7.6 Visual_SetLayer
The Visual_SetLayer message sets the layer number of the visual.
The layer value is between 0x00000000 (the back-most layer) and 4294967295 (the front-most layer) of the visual.
The fields of the Visual_SetLayer are specified in section 2.2.4.6.6.
The common header fields are specified in section 2.2.4.