code: def lights(self):
          
          if not hasattr(self, '_lights') or self._lights is None:
              # do some automatic lighting
              lights, transforms = lighting.autolight(self)
              # assign the transforms to the scene graph
              for L, T in zip(lights, transforms):
                  self.graph[L.name] = T
              # set the lights
              self._lights = lights
          return self._lights
docs: Get a list of the lights in the scene. If nothing is
          set it will generate some automatically.
  
          Returns
          -------------
          lights : [trimesh.scene.lighting.Light]
            Lights in the scene.