`val return : 'a ‑> 'a Async_kernel__.Types.Deferred.t`
`val bind : 'a Async_kernel__.Types.Deferred.t ‑> f:('a ‑> 'b Async_kernel__.Types.Deferred.t) ‑> 'b Async_kernel__.Types.Deferred.t`
`val map : 'a Async_kernel__.Types.Deferred.t ‑> f:('a ‑> 'b) ‑> 'b Async_kernel__.Types.Deferred.t`
`val both : 'a Async_kernel__.Types.Deferred.t ‑> 'b Async_kernel__.Types.Deferred.t ‑> ('a * 'b) Async_kernel__.Types.Deferred.t`
`module Open_on_rhs : sig ... end`