code: static Class<?> getKeyTypeFromEnumMap(Object enumMap)
      {
          if(__keyTypeFromEnumMap == null)
          {
              throw new RuntimeException("Could not access (reflection) the private " +
                      "field *keyType* (enumClass) from: class java.util.EnumMap");
          }
          
          try
          {
              return (Class<?>)__keyTypeFromEnumMap.get(enumMap);
          }
          catch (IllegalArgumentException e)
          {
              throw new RuntimeException(e);
          }
          catch (IllegalAccessException e)
          {
              throw new RuntimeException(e);
          }
      }
docs: Retrieves the enum key type from the EnumMap via reflection.
  This is used by {@link ObjectSchema}.