code: def setup_class(cls):
      if pdf_output:
          from matplotlib.backends.backend_pdf import PdfPages
  
          cls.pdf = PdfPages("predict_functional.pdf")
  
file_path: statsmodels/statsmodels/sandbox/tests/test_predict_functional.py
imports: from statsmodels.sandbox.predict_functional import predict_functional
  import numpy
  import pandas
  import pytest
  import statsmodels.api
label_desc: Use image node_id 1 for calling the TestPredFunc obj's underlying member method code with example usage: obj.setup_class(cls) without return types