class_docstr: DataQueue test
code: def test_empty_scalar_with_ques(self):
      que = DataQueue(
          [
              ("url", ColumnType.SCALAR),
              ("image", ColumnType.SCALAR),
              ("vec", ColumnType.QUEUE),
          ]
      )
      que.put(("http://towhee.io", Empty(), 1))
      que.put(("http://towhee.io", Empty(), 2))
      que.put(("http://towhee.io", Empty(), 3))
      self.assertEqual(que.size, 0)
      que.seal()
      self.assertEqual(que.size, 3)
      self.assertEqual(
          que.to_list(),
          [
              ["http://towhee.io", Empty(), 1],
              ["http://towhee.io", Empty(), 2],
              ["http://towhee.io", Empty(), 3],
          ],
      )
  
imports: import unittest
  import threading
  import time
  from functools import partial
  from towhee.runtime.data_queue import DataQueue, ColumnType, Empty
label_desc: Use image node_id 20 for calling the TestDataQueue obj's underlying member method code with example usage: obj.test_empty_scalar_with_ques() without return types