code: def a_test_ppc():
      model = pf.EGARCHMReg(formula="JPM~Rf", data=data, p=1, q=1)
      x = model.fit("BBVI", iterations=100)
      p_value = model.ppc()
      assert 0.0 <= p_value <= 1.0
  
imports: import numpy
  import pyflux
  import pandas
  from pandas.io.data import DataReader
  from datetime import datetime
label_desc: Use image node_id 23 for calling a global function with example usage: a_test_ppc() without return types