code: def test_nonunique_output():
      with pytest.raises(ValueError, match="ambiguous"):
          Pipenet(
              {
                  "deseasonal_residual": {
                      "model": (
                          transformer.ClassicSeasonalDecomposition(
                              freq=6
                          )
                      ),
                      "input": "original",
                  },
                  "abs_residual": {
                      "model": transformer.CustomizedTransformer1D(
                          transform_func=abs
                      ),
                      "input": "deseasonal_residual",
                  },
                  "iqr_ad": {
                      "model": detector.InterQuartileRangeAD(
                          c=(None, 3)
                      ),
                      "input": "abs_residual",
                  },
                  "sign_check": {
                      "model": detector.ThresholdAD(
                          high=0.0, low=-float("inf")
                      ),
                      "input": "deseasonal_residual",
                  },
              }
          )
  
file_path: adtk/tests/test_pipe.py
imports: import numpy
  import pandas
  import pytest
  from sklearn.linear_model import LinearRegression
  import adtk.aggregator
  import adtk.detector
  import adtk.transformer
  from adtk.pipe import Pipeline, Pipenet
label_desc: Use image node_id 6 for calling a global function with example usage: test_nonunique_output() without return types