class_docstr: Test pipelines contain different kinds of node.
class_docstr_tok: ["Test","pipelines","contain","different","kinds","of","node","."]
code: def test_zero_timestamp(self):
      runtime_pipeline = RuntimePipeline(self.dag_dict)
      result = runtime_pipeline([1, 1, 1, 1, 1, 1], [])
      for i in range(6):
          self.assertEqual(
              result.get(), [1, 6 if i < 1 else Empty(), 0]
          )
  
imports: import unittest
  import copy
  from itertools import zip_longest
  from towhee.runtime.runtime_pipeline import RuntimePipeline
  from towhee.runtime.data_queue import Empty
label_desc: Use image node_id 3 for calling the TestTimeWindowPipeline obj's underlying member method code with example usage: obj.test_zero_timestamp() without return types