Exception in thread "main" java.lang.IndexOutOfBoundsException: Index 0 out-of-bounds for length 0
	at java.base/jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:64)
	at java.base/jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:70)
	at java.base/jdk.internal.util.Preconditions.checkIndex(Preconditions.java:248)
	at java.base/java.util.Objects.checkIndex(Objects.java:372)
	at java.base/java.util.ArrayList.get(ArrayList.java:439)
	at Baza$Polaczenie.getInstance(Baza.java:29)
	at Baza.getPolaczenie(Baza.java:15)
	at Klient.main(Klient.java:8)