public bool TryMaintainNewZayavka(Zayavka zayavka) { if (zayavka == null) { return(false); } var obrabotchikToAddZayavka = Obrabotchiks.FirstOrDefault(obrabotchik => obrabotchik.Zayavka == null); if (obrabotchikToAddZayavka == null) { return(Nakopitel.TryToAddZayavka(zayavka)); } obrabotchikToAddZayavka.Zayavka = zayavka; return(true); }