module Sqlexpr_concurrency:sig..end
module type THREAD_LOCAL_STATE =sig..end
module type THREAD =sig..end
module Id:THREADwith type 'a t = 'a and type 'a key = 'a Lwt.key
module Lwt:THREADwith type 'a t = 'a Lwt.t and type 'a key = 'a Lwt.key