class_docstr: Test RuntimePipeline in Pipeline
class_docstr_tok: ["Test","RuntimePipeline","in","Pipeline"]
code: def test_multi_output(self):
      p_1 = (
          pipe.input("x")
          .map("x", ("x", "y", "z"), lambda x: (x, x + 2, x + 3))
          .map("x", "x", lambda x: x + 1)
          .output("x", "y", "z")
      )
  
      p = (
          pipe.input("x")
          .map("x", ("x", "y", "z"), p_1)
          .output("x", "y", "z")
      )
      res = p(1).get()
      self.assertEqual(res, [2, 3, 4])
  
      p = pipe.input("x").map("x", "z", p_1).output("z")
      res = p(1).get()
      self.assertEqual(res, [(2, 3, 4)])
  
file_path: towhee/tests/unittests/runtime/test_dag_pipeline.py
imports: import unittest
  from towhee import pipe
label_desc: Use image node_id 5 for calling the TestDAGPipeline obj's underlying member method code with example usage: obj.test_multi_output() without return types