code: def setUp(self):
      np.random.seed(42)
      self.simple_df = pd.DataFrame(
          (np.random.random((20, 10)) > 0.5), columns=range(0, 10)
      ).replace(False, np.nan)
  
imports: import unittest
  import pandas
  import numpy
  import pytest
  import sys
  import missingno
  import matplotlib.pyplot
label_desc: Use image node_id 1 for calling the TestBar obj's underlying member method code with example usage: obj.setUp() without return types