S.Blocksval path : (prefix, prefix) Mavryk_rpc.Path.tval list :
([ `GET ],
prefix,
prefix,
< heads : Mavryk_base.TzPervasives.Block_hash.t list
; length : int option
; min_date : Mavryk_base.Time.Protocol.t option >,
unit,
Mavryk_base.TzPervasives.Block_hash.t list list)
Mavryk_rpc.Service.t