in src/main/java/org/apache/sling/maven/bundlesupport/JsonSupport.java [97:111]
public static void accumulate(Map<String, Object> obj, String name, String value) {
Object current = obj.get(name);
if (current == null) {
obj.put(name, value);
} else if (current instanceof List) {
List<String> array = new ArrayList<>((List) current);
array.add(value);
obj.put(name, array);
} else {
List<String> array = new ArrayList<>();
array.add((String) current);
array.add(value);
obj.put(name, array);
}
}