public FirstDeep(ISecondDeep secondDeep)
 {
     this.secondDeep = secondDeep;
 }
 readonly ISecondDeep secondDeep;      //egzemplarz interfejsu
 public FirstDeep(ISecondDeep secDeep) //injekcja w konstruktorze
 {
     secDeep = secondDeep;             //przypisanie parametru
 }
 public FirstDeep(ISecondDeep oa)
 {
     this.oa = oa;
 }