public void CreateInvoice(Member playerOne, Member playerTwo) { var fortKnox = FortKnox.Instance(); if (!_competition.IsParticipant(playerOne)) { fortKnox.NewInvoice(playerOne, _competition.Fee); _competition.AddParticipant(playerOne); } if (!_competition.IsParticipant(playerTwo)) { fortKnox.NewInvoice(playerTwo, _competition.Fee); _competition.AddParticipant(playerTwo); } fortKnox.NewInvoice(playerOne, _matchFee); fortKnox.NewInvoice(playerTwo, _matchFee); }