`type key = String.t`
`type !'a t = 'a Stdlib__Map.Make(String).t`
`val empty : 'a t`
`val add : key -> 'a -> 'a t -> 'a t`
`val add_to_list : key -> 'a -> 'a list t -> 'a list t`
`val update : key -> ('a option -> 'a option) -> 'a t -> 'a t`
`val singleton : key -> 'a -> 'a t`
`val remove : key -> 'a t -> 'a t`
`val merge : (key -> 'a option -> 'b option -> 'c option) -> 'a t -> 'b t -> 'c t`
`val union : (key -> 'a -> 'a -> 'a option) -> 'a t -> 'a t -> 'a t`
`val cardinal : 'a t -> int`
`val bindings : 'a t -> (key * 'a) list`
`val min_binding : 'a t -> key * 'a`
`val min_binding_opt : 'a t -> (key * 'a) option`
`val max_binding : 'a t -> key * 'a`
`val max_binding_opt : 'a t -> (key * 'a) option`
`val choose : 'a t -> key * 'a`
`val choose_opt : 'a t -> (key * 'a) option`
`val find : key -> 'a t -> 'a`
`val find_opt : key -> 'a t -> 'a option`
`val find_first : (key -> bool) -> 'a t -> key * 'a`
`val find_first_opt : (key -> bool) -> 'a t -> (key * 'a) option`
`val find_last : (key -> bool) -> 'a t -> key * 'a`
`val find_last_opt : (key -> bool) -> 'a t -> (key * 'a) option`
`val iter : (key -> 'a -> unit) -> 'a t -> unit`
`val fold : (key -> 'a -> 'acc -> 'acc) -> 'a t -> 'acc -> 'acc`
`val map : ('a -> 'b) -> 'a t -> 'b t`
`val mapi : (key -> 'a -> 'b) -> 'a t -> 'b t`
`val filter : (key -> 'a -> bool) -> 'a t -> 'a t`
`val filter_map : (key -> 'a -> 'b option) -> 'a t -> 'b t`
`val partition : (key -> 'a -> bool) -> 'a t -> 'a t * 'a t`
`val split : key -> 'a t -> 'a t * 'a option * 'a t`
`val is_empty : 'a t -> bool`
`val mem : key -> 'a t -> bool`
`val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool`
`val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int`
`val for_all : (key -> 'a -> bool) -> 'a t -> bool`
`val exists : (key -> 'a -> bool) -> 'a t -> bool`
`val to_list : 'a t -> (key * 'a) list`
`val of_list : (key * 'a) list -> 'a t`
`val to_seq : 'a t -> (key * 'a) Stdlib.Seq.t`
`val to_rev_seq : 'a t -> (key * 'a) Stdlib.Seq.t`
`val to_seq_from : key -> 'a t -> (key * 'a) Stdlib.Seq.t`
`val add_seq : (key * 'a) Stdlib.Seq.t -> 'a t -> 'a t`
`val of_seq : (key * 'a) Stdlib.Seq.t -> 'a t`