Add punishments and container

src/main/java/de/shiewk/smoderation/storage/PunishmentContainer.java

@@ -0,0 +1,39 @@
+package de.shiewk.smoderation.storage;
+
+import de.shiewk.smoderation.punishments.Punishment;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.function.Predicate;
+
+public class PunishmentContainer {
+
+    private final CopyOnWriteArrayList<Punishment> punishments = new CopyOnWriteArrayList<>();
+
+    public PunishmentContainer(){}
+
+    public void add(Punishment punishment){
+        punishments.add(punishment);
+    }
+
+    public @Nullable Punishment remove(int index){
+        return punishments.remove(index);
+    }
+
+    public boolean remove(Punishment punishment){
+        return punishments.remove(punishment);
+    }
+
+    public @Nullable Punishment find(Predicate<Punishment> predicate){
+        for (Punishment punishment : new CopyOnWriteArrayList<>(punishments)) {
+            if (predicate.test(punishment)){
+                return punishment;
+            }
+        }
+        return null;
+    }
+
+    public @Nullable Punishment findByTimestamp(long timestamp){
+        return find(punishment -> punishment.time == timestamp);
+    }
+}