Belt_internalBucketsType
type 'a opt = 'a Js.undefined
type ('hash, 'eq, 'c) container = {
mutable size : int;
mutable buckets : 'c opt array;
hash : 'hash;
eq : 'eq;
}
val toOpt : 'a opt -> 'a option
val return : 'a -> 'a opt
val emptyOpt : 'a Js.undefined
val make : hash:'hash -> eq:'eq -> hintSize:int -> ('hash, 'eq, _) container
val clear : (_, _, _) container -> unit
val isEmpty : (_, _, _) container -> bool