code: @SuppressWarnings("unchecked")
      private static Object getMappedValue(Object obj, Property property, Object key) {
          if (property == null) {
              throw new IllegalArgumentException("Cannot get the mapped value from a 'null' property.");
          }
  
          if (property.getType().isAssignableFrom(Map.class)) {
              Map<Object, Object> map = (Map<Object, Object>) property.get(obj);
  
              if (map == null) {
                  throw new NullPointerException("Invalid 'null' value found for mapped " + property + " in "
                                                         + obj.getClass().getName() + ".");
  
              }
  
              return map.get(key);
          } else {
              throw new IllegalArgumentException("Cannot get a mapped value from the not mapped " + property
                                                         + ". Only Map type is supported, but " + property.getType().getSimpleName() + " found.");
          }
      }
docs: /*
  Internal: Static version of {@link ObjectWrapper#getMappedValue(Property, Object)}.