code: def test_independent_variable_singular(model):
      data1 = data.copy()
      data1["dup"] = data1["Drug"]
      mod = model.from_formula(
          "Histamine0 + Histamine1 + Histamine3 + Histamine5 ~ Drug * dup",
          data1,
      )
      assert_raises(ValueError, mod.fit)
      mod = model.from_formula(
          "Histamine0 + Histamine1 + Histamine3 + Histamine5 ~ Drug * dup",
          data1,
      )
      assert_raises(ValueError, mod.fit)
  
imports: import os.path
  import numpy
  import pandas
  import pytest
  from statsmodels.regression.linear_model import OLS
  from statsmodels.multivariate.multivariate_ols import _MultivariateOLS, MultivariateLS
  from numpy.testing import assert_allclose, assert_array_almost_equal, assert_raises
  import patsy
label_desc: Use image node_id 4 for calling a global function with example usage: test_independent_variable_singular(model) without return types