Remove boolean and floats from supported key types

    }

    switch (schemaType) {

      case BOOLEAN:

      case INT8:

      case INT16:

      case INT32:

      case INT64:

      case FLOAT32:

      case FLOAT64:

      case STRING:

        return String.valueOf(key);

      default:

        // TODO: support more key types, also should we support BOOLEAN and FLOAT at all?

        throw new DataException(schemaType.name() + "is not supported as the document id.");

    }

  }