completed message persistence

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

core/src/main/java/de/srsoftware/umbrella/core/model/Envelope.java

@@ -22,7 +22,7 @@ import org.json.JSONObject;
 public class Envelope<T extends Message<?>> {
 	private final T message;
 	private final Set<User> receivers;
-	private final LocalDateTime time;
+	private LocalDateTime time;
 	private final long id;
 
 	public Envelope(long id, T message, User receiver){
@@ -73,7 +73,7 @@ public class Envelope<T extends Message<?>> {
 	}
 
 	public boolean isFor(User receiver) {
-		return receivers.contains(receiver);
+		return receivers.stream().anyMatch(r -> r.equals(receiver));
 	}
 
 	public T message(){
@@ -84,6 +84,11 @@ public class Envelope<T extends Message<?>> {
 		return receivers;
 	}
 
+	public Envelope<T> time(LocalDateTime timestamp){
+		this.time = timestamp;
+		return this;
+	}
+
 	public LocalDateTime time(){
 		return time;
 	}

core/src/main/java/de/srsoftware/umbrella/core/model/UmbrellaUser.java

@@ -25,11 +25,14 @@ public class UmbrellaUser extends User implements Mappable, Owner {
 
 	@Override
 	public boolean equals(Object o) {
-		if (!(o instanceof UmbrellaUser user)) return false;
-		return Objects.equals(email(), user.email())
-				&& Objects.equals(name(), user.name())
-				&& Objects.equals(id, user.id)
-				&& Objects.equals(language(), user.language());
+		if (o instanceof UmbrellaUser user) {
+			return Objects.equals(email(), user.email())
+					&& Objects.equals(name(), user.name())
+					&& Objects.equals(id, user.id)
+					&& Objects.equals(language(), user.language());
+		}
+		if (o instanceof User user) return user.equals(this);
+		return false;
 	}
 
 	@Override