class_docstr: Test diff col size
class_docstr_tok: ["Test","diff","col","size"]
code: def test_filter(self):
      p1 = Pipeline.input("a", "b")
      p2 = p1.flat_map("a", "a1", lambda x: x)
      p3 = p1.flat_map("b", "b1", lambda x: x)
      p = (
          p3.concat(p2)
          .filter(("a1", "b1"), ("a1", "b1"), "a1", lambda x: x > 5)
          .output("a1", "b1")
      )
      print(p([1, 3, 5, 7, 9], [2] * 20).to_list())
  
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 TestPipelineDiffColSize obj's underlying member method code with example usage: obj.test_filter() without return types