Cmdliner_clineCommand lines.
val create : 
  ?peek_opts:bool ->
  legacy_prefixes:bool ->
  for_completion:bool ->
  Cmdliner_def.Arg_info.Set.t ->
  string list ->
  [ `Ok of Cmdliner_def.Cline.t
  | `Complete of Cmdliner_def.Complete.t * Cmdliner_def.Cline.t
  | `Error of string * Cmdliner_def.Cline.t ]