code: def test_residplot(self):
      x, y = self.df.x, self.df.y
      ax = lm.residplot(x=x, y=y)
  
      resid = y - np.polyval(np.polyfit(x, y, 1), x)
      x_plot, y_plot = ax.collections[0].get_offsets().T
  
      npt.assert_array_equal(x, x_plot)
      npt.assert_array_almost_equal(resid, y_plot)
  
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 16 for calling the TestRegressionPlots obj's underlying member method code with example usage: obj.test_residplot() without return types