code: def mkacf():
      return pd.DataFrame(
          {
              "lag": range(41),
              "correlation": np.random.random(41),
              "low": np.random.random(41),
              "up": np.random.random(41),
          }
      )
  
file_path: tslumen/tests/unit/report/util.py
imports: import datetime
  import copy
  import numpy
  import pandas
  from tslumen.profile.base import BundledResult, BundledResultDetails
  from tslumen.profile.stat_tests import TestResult
label_desc: Use image node_id 2 for calling a global function with example usage: mkacf() and returns: pd