docstr: Test that drawing a best fit line works.
docstr_tok: ["Test","that","drawing","a","best","fit","line","works","."]
code: def test_draw_best_fit(self):
      """
      Test that drawing a best fit line works.
      """
      fig, ax = plt.subplots()
      X, y = ANSCOMBE[0]
  
      assert ax == draw_best_fit(X, y, ax, "linear")
      assert ax == draw_best_fit(X, y, ax, "quadratic")
  
file_path: yellowbrick/tests/test_bestfit.py
imports: import pytest
  import numpy
  import matplotlib.pyplot
  from tests.base import VisualTestCase
  from yellowbrick.bestfit import *
  from yellowbrick.anscombe import ANSCOMBE
  from yellowbrick.exceptions import YellowbrickValueError
  from sklearn.linear_model import LinearRegression
  from sklearn.pipeline import Pipeline
label_desc: Use image node_id 3 for calling the TestBestFit obj's underlying member method code with example usage: obj.test_draw_best_fit() without return types