code: def test_scatter3d_colorbar_label(self):
      scatter3d = Scatter3D([(0, 1, 2), (1, 2, 3), (2, 3, 4)]).opts(
          color="z", colorbar=True
      )
      plot = mpl_renderer.get_plot(scatter3d)
      assert plot.handles["cax"].get_ylabel() == "z"
  
file_path: holoviews/holoviews/tests/plotting/matplotlib/test_scatter3d.py
imports: from holoviews.element import Scatter3D
  from .test_plot import TestMPLPlot, mpl_renderer
label_desc: Use image node_id 1 for calling the TestPointPlot obj's underlying member method code with example usage: obj.test_scatter3d_colorbar_label() without return types