code: @Override
      public Object valAt(Object o) {
          try {
              if (o instanceof Keyword) {
                  return getValueByField(((Keyword) o).getName());
              } else if (o instanceof String) {
                  return getValueByField((String) o);
              }
          } catch (IllegalArgumentException ignored) {
          }
          return null;
      }
docs: /* ILookup