preparing to show pages to guests

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

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

@@ -5,12 +5,17 @@ package de.srsoftware.umbrella.core.model;
 import static de.srsoftware.umbrella.core.Constants.*;
 
 import de.srsoftware.tools.Mappable;
+
+import java.util.HashMap;
 import java.util.Map;
 
 public record Member(UmbrellaUser user, Permission permission) implements Mappable {
 	@Override
 	public Map<String, Object> toMap() {
-		return Map.of(USER,user.toMap(),PERMISSION,permission.toMap());
+		var map = new HashMap<String,Object>();
+		map.put(USER,user == null ? null : user.toMap());
+		map.put(PERMISSION,permission.toMap());
+		return map;
 	}
 
 	public boolean mayWrite() {