`Monad_sequence.S` is a generic interface specifying functions that deal with a container and a monad. It is specialized to the `Deferred` monad and used with various containers in modules `Deferred.Array`, `Deferred.List`, `Deferred.Queue`, and `Deferred.Sequence`. The `Monad_sequence.how` type specifies the parallelism of container iterators.

`type how` = `[`

`|` ``Parallel`
`|` ``Sequential`
`|` ``Max_concurrent_jobs of int`

`]```
`val sexp_of_how : how ‑> Base.Sexp.t`
`module type S : sig ... end`