module CCHet:sig..end
    This is similar to CCMixtbl, but the injection is directly used as
    a key.
Since 0.17
type'asequence =('a -> unit) -> unit
type'agen =unit -> 'a option
module Key:sig..end
type pair = 
| | 
Pair :  | 
module Tbl:sig..end
CCHet.Key
module Map:sig..end