type, which is currently "jpeg",
"tiff", "png", "ico" or "bmp". See gdkPixbufSaveToBuffer
for more details.gdkPixbufSaveToBufferv(object, type, option.keys, option.values, .errwarn = TRUE)objectGdkPixbuf.typeoption.keysNULL-terminatedoption.valuesbufferbuffer.sizeerrorNULL. [ allow-none ]