code: @SuppressWarnings("unchecked")
      private static void setMappedValue(Object obj, Property property, Object key, Object value, ObjectWrapper options) {
          if (property == null) {
              throw new IllegalArgumentException("Cannot set a new mapped value to a 'null' property.");
          }
  
          if (Map.class.isAssignableFrom(property.getType())) {
              Map map = (Map) property.get(obj);
  
              if (map == null) {
                  if (options.isAutoInstancing) {
                      map = new LinkedHashMap();
                      property.set(obj, map);
                  } else {
                      throw new NullPointerException("Invalid 'null' value found for the mapped '" + property + "' in "
                                                             + obj.getClass().getName() + " object.");
                  }
              }
  
              map.put(key, value);
          } else {
              throw new IllegalArgumentException("Cannot set a new mapped value to " + property
                                                         + ". Only Map type is supported for mapped properties, but " + property.getType().getName()
                                                         + " found.");
          }
      }
docs: /*
  Internal: Static version of {@link ObjectWrapper#setMappedValue(Property, Object, Object)}.