Mavryk_baking_002_PtBoreas.Baking_vdfval start_vdf_worker :
Mavryk_client_002_PtBoreas.Protocol_client_context.full ->
canceler:Lwt_canceler.t ->
Mavryk_protocol_002_PtBoreas.Protocol.Alpha_context.Constants.t ->
Mavryk_shell_services.Chain_services.chain ->
unit Mavryk_base.TzPervasives.tzresult Lwt.t