You can search for identifiers within the package.
in-package search v0.2.0
val error_to_string : [< `Disconnected | `Is_read_only | `Unimplemented | `Unknown of string ] -> string
val random : (module V1_LWT.BLOCK with type t = 'a) -> 'a -> [> `Error of [> `Msg of string ] | `Ok of unit ] Lwt.t