code: def volume(self, vol, clim=None, method='mip', threshold=None,
                 cmap='grays'):
          
          self._configure_3d()
          volume = scene.Volume(vol, clim, method, threshold, cmap=cmap)
          self.view.add(volume)
          self.view.camera.set_range()
          return volume
docs: Show a 3D volume
  
          Parameters
          ----------
          vol : ndarray
              Volume to render.
          clim : tuple of two floats | None
              The contrast limits. The values in the volume are mapped to
              black and white corresponding to these values. Default maps
              between min and max.
          method : {'mip', 'iso', 'translucent', 'additive'}
              The render style to use. See corresponding docs for details.
              Default 'mip'.
          threshold : float
              The threshold to use for the isosurafce render style. By default
              the mean of the given volume is used.
          cmap : str
              The colormap to use.
  
          Returns
          -------
          volume : instance of Volume
              The volume visualization.
  
          See also
          --------
          Volume