code: def adf20(x):
      return adfuller(x, 2, regression="n", autolag=None)
  
file_path: statsmodels/statsmodels/sandbox/tools/try_mctools.py
imports: from statsmodels.compat.python import lrange
  import numpy
  from scipy import stats
  from statsmodels.sandbox.tools.mctools import StatTestMC
  from statsmodels.stats.diagnostic import acorr_ljungbox
  from statsmodels.tsa.stattools import adfuller
label_desc: Use image node_id 4 for calling a global function with example usage: adf20(x) and returns: adfuller