object
method client_addr : Unix.sockaddr option
method credential : string * string
method frame_len : int
method message : Rpc_packer.packed_value
method procedure : Netnumber.uint4
method program : Netnumber.uint4
method server_addr : Unix.sockaddr option
method transport_user : string option
method verifier : string * string
method version : Netnumber.uint4
method xid : Netnumber.uint4
end
