You can search for identifiers within the package.
in-package search v0.2.0
module type THREAD_LOCAL_STATE = sig ... end
module type THREAD = sig ... end
module Id : THREAD with type 'a t = 'a and type 'a key = 'a Lwt.key
module Lwt : THREAD with type 'a t = 'a Lwt.t and type 'a key = 'a Lwt.key