DataSetAggregateWithNullValuesRule fails creating null literal for non-nullable type

@Test
  def testTableAggregationWithMultipleTableAPI(): Unit = {
    val env = ExecutionEnvironment.getExecutionEnvironment
    val tEnv = TableEnvironment.getTableEnvironment(env, config)

    val inputTable = CollectionDataSets.getSmallNestedTupleDataSet(env).toTable(tEnv, 'a, 'b)
    tEnv.registerDataSet("MyTable", inputTable)

    val result = tEnv.scan("MyTable")
      .where('a.get("_1") > 0)
      .select('a.get("_1").avg, 'a.get("_2").sum, 'b.count)

    val expected = "2,6,3"
    val results = result.toDataSet[Row].collect()
    TestBaseUtils.compareResultAsText(results.asJava, expected)
  }