class_docstr: Test no outputs.
class_docstr_tok: ["Test","no","outputs","."]
code: def test_window_all(self):
      p = (
          Pipeline.input("a")
          .flat_map("a", "a", lambda x: x)
          .window_all("a", (), sum)
          .output("a")
      )
  
      self.assertEqual(p([1, 2, 3, 4]).to_list(), [[1], [2], [3], [4]])
  
imports: import unittest
  from towhee.operator.nop import NOPNodeOperator
  from towhee.operator import PyOperator
  from towhee.runtime.pipeline import Pipeline
  from towhee.runtime.data_queue import Empty
  from towhee.runtime import ops, register
  from towhee.runtime.runtime_pipeline import RuntimePipeline
label_desc: Use image node_id 3 for calling the TestPipelineNoOutputCol obj's underlying member method code with example usage: obj.test_window_all() without return types