code: def test_custom_ndarray_neighbour_matrix():
      iris = datasets.load_iris()
      x = iris.data
      y = iris.target
  
      class_indicies = {
          label: np.argwhere(y == label).ravel()
          for label in np.unique(y)
      }
      neighbour_matrix = np.array(
          [class_indicies[label] for label in y]
      )
  
      ivis_iris = Ivis(epochs=5, neighbour_matrix=neighbour_matrix)
      ivis_iris.k = 15
      ivis_iris.batch_size = 16
  
      y_pred_iris = ivis_iris.fit_transform(x)
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_custom_ndarray_neighbour_matrix() without return types