class_docstr: Test the JointPlot visualizer with histograms
class_docstr_tok: ["Test","the","JointPlot","visualizer","with","histograms"]
docstr: When self.columns=[str, str] image similarity on pandas dataset no y
docstr_tok: ["When","self.columns=","[","str",",","str","]","image","similarity","on","pandas","dataset","no","y"]
code: def test_columns_double_str_index_pandas_no_y_hist(self):
      """
      When self.columns=[str, str] image similarity on pandas dataset no y
      """
      oz = JointPlot(columns=["a", "b"], hist=True)
      X = pd.DataFrame(self.continuous.X, columns=["a", "b"])
      assert oz.fit(X, y=None) is oz
      assert hasattr(oz, "corr_")
  
      oz.finalize()
      self.assert_images_similar(oz)
  
imports: import sys
  import pytest
  import numpy
  from functools import partial
  from unittest.mock import patch, MagicMock
  from sklearn.datasets import make_classification, make_regression
  from tests.base import IS_WINDOWS_OR_CONDA, VisualTestCase
  from yellowbrick.exceptions import YellowbrickValueError
  from yellowbrick.features.jointplot import *
  from ..fixtures import Dataset
label_desc: Use image node_id 7 for calling the TestJointPlotHistogram obj's underlying member method code with example usage: obj.test_columns_double_str_index_pandas_no_y_hist() without return types