`object
method auth_protocol : Rpc_client.auth_protocol
method next_credentials :
Rpc_client.t ->
Rpc_program.t ->
string ->
Netnumber.uint4 ->
string * string * string * string * Netxdr.encoder option *
Netxdr.decoder option
method server_accepts :
Rpc_client.t -> Netnumber.uint4 -> string -> string -> unit
method server_rejects :
Rpc_client.t ->
Netnumber.uint4 -> Rpc.server_error -> Rpc_client.reject_code
end`