@Override
  public StreamsMaterializedTable nonWindowed() {
    if (windowInfo.isPresent()) {
      throw new UnsupportedOperationException("Table has windowed key");
    }
    return new KsMaterializedTable(stateStore);
  }
@Test(expected = UnsupportedOperationException.class)
  public void shouldThrowOnNonWindowedIfWindowed() {
    // Given:
    givenWindowType(Optional.of(WindowType.SESSION));

    // When:
    materialization.nonWindowed();
  }