class_docstr: Unit test multi decorator Class
  TODO: Docstring
docstr: Unit test combine masks
  TODO: mock_delegate description
  Parameters
  ----------
  mock_delegate : [type]
      [description]
docstr_tok: ["Unit","test","combine","masks","TODO",":","mock_delegate","description","Parameters","--","--","--","--","--","mock_delegate",":","[","type","]","[","description","]"]
code: def test_combine_masks(self, mock_delegate):
      """
      Unit test combine masks
      TODO: mock_delegate description
      Parameters
      ----------
      mock_delegate : [type]
          [description]
      """
      backend = Mock()
      df1 = np.array([[1, 2, 3], [4, 5, 6]])
      df2 = np.array([[-1, -2, -3], [-4, -5, -6]])
      df3 = np.array([[10, 20, 30], [40, 50, 60]])
      df4 = np.array([[-10, -20, -30], [-40, -50, -60]])
      df5 = np.array([[100, 200, 300], [400, 500, 600]])
      df6 = np.array([[-100, -200, -300], [-400, -500, -600]])
      masks = [[df1, df2], [df3, df4], [df5, df6]]
      transposed_masks = [[df1, df3, df5], [df2, df4, df6]]
      backend.combine_masks = Mock()
      state = MultiDecorator(backend)
      state.combine_masks(masks)
      mock_delegate.assert_called_with(
          "combine_masks", transposed_masks
      )
  
imports: import unittest
  from unittest.mock import patch, Mock
  import numpy
  import pandas
  from shapash.explainer.multi_decorator import MultiDecorator
label_desc: Use image node_id 9 for calling the TestMultiDecorator obj's underlying member method code with example usage: obj.test_combine_masks(mock_delegate) without return types