code: def test_variables_must_be_1d(self):
      array_2d = np.random.randn(20, 2)
      array_1d = np.random.randn(20)
      with pytest.raises(ValueError):
          lm._RegressionPlotter(array_2d, array_1d)
      with pytest.raises(ValueError):
          lm._RegressionPlotter(array_1d, array_2d)
  
imports: import warnings
  import numpy
  import matplotlib
  import matplotlib.pyplot
  import pandas
  import pytest
  import numpy.testing
  import pandas.testing
  from seaborn import regression
  from seaborn.palettes import color_palette
label_desc: Use image node_id 4 for calling the TestRegressionPlotter obj's underlying member method code with example usage: obj.test_variables_must_be_1d() without return types