Wl_shm.v2Handler for a proxy with version >= 2.
constraint 'a = [< `V2 ]method private virtual on_format : [> `V2 ] t ->
format:{Imports}1.Wl_shm.Format.t ->
unitPixel format description.
Informs the client about a valid pixel format that can be used for buffers. Known formats include argb8888 and xrgb8888.