AwsQuery.Requestval make : 
  (module Http.Client_intf
    with type t = 'http_t
     and type Body.t = 'body_t
     and type Response.t = 'response_t) ->
  service:Service.descriptor ->
  config:Config.t ->
  action:string ->
  fields:field option list ->
  http:'http_t ->
  ('response_t * 'body_t, Smaws_Lib__Http.http_failure) Stdlib.result