class_docstr: Test RuntimePipeline in Pipeline
class_docstr_tok: ["Test","RuntimePipeline","in","Pipeline"]
code: def test_filter(self):
      p_1 = pipe.input("x").map("x", "y", lambda x: x > 3).output("y")
      p = (
          pipe.input("x")
          .flat_map("x", "x", p4)
          .filter("x", "x", "x", p_1)
          .output("x")
      )
      res = p(4).to_list()
      self.assertEqual(res, [[4]])
  
      p = (
          pipe.input("x")
          .flat_map("x", "y", p4)
          .map("y", "z", lambda x: x * 100)
          .filter("z", "zr", "y", p_1)
          .output("zr")
      )
      res = p(4).to_list()
      self.assertEqual(res, [[400]])
  
file_path: towhee/tests/unittests/runtime/test_dag_pipeline.py
imports: import unittest
  from towhee import pipe
label_desc: Use image node_id 7 for calling the TestDAGPipeline obj's underlying member method code with example usage: obj.test_filter() without return types