def METHOD_NAME(self):
    xs = [0, 1, 2]
    ys = [2, 1, 0]
    data = np.array([[0,1,2], [3,4,5], [6,7,8]])
    flattened = np.array([6, 3, np.NaN, 7, 4, 1, 8, 5, 2])
    qmesh = QuadMesh((xs, ys, data)).opts(nodata=0)
    plot = bokeh_renderer.get_plot(qmesh)
    source = plot.handles['source']
    self.assertEqual(source.data['z'], flattened)