code: def test_iqr(self):
      assert_almost_equal(scale.iqr(self.chem), 0.68570, DECIMAL)
  
imports: import numpy
  from numpy.random import standard_normal
  from numpy.testing import assert_almost_equal, assert_equal
  import pytest
  from scipy.stats import norm
  import statsmodels.api
  import statsmodels.robust.scale
  from statsmodels.robust.scale import mad
label_desc: Use image node_id 5 for calling the TestChem obj's underlying member method code with example usage: obj.test_iqr() without return types