method cache ?key ?url ?debug () =
let args = ref [] in
may (fun v ->
args := sv_of_string "key" :: sv_of_string v :: !args) key;
may (fun v ->
args := sv_of_string "url" :: sv_of_string v :: !args) url;
may (fun v ->
args := sv_of_string "debug" :: sv_of_int v :: !args) debug;
let sv = call_method sv "cache" !args in
new net_google_cache sv