code: def get_transform(self, map_from='visual', map_to='render'):
          
          tr = ['visual', 'scene', 'document', 'canvas', 'framebuffer', 'render']
          ifrom = tr.index(map_from)
          ito = tr.index(map_to)
          
          if ifrom < ito:
              trs = [getattr(self, '_' + t + '_transform')
                     for t in tr[ifrom:ito]][::-1]
          else:
              trs = [getattr(self, '_' + t + '_transform').inverse
                     for t in tr[ito:ifrom]]
          return self._cache.get(trs)
docs: Return a transform mapping between any two coordinate systems.
          
          Parameters
          ----------
          map_from : str
              The starting coordinate system to map from. Must be one of: visual,
              scene, document, canvas, framebuffer, or render.
          map_to : str
              The ending coordinate system to map to. Must be one of: visual,
              scene, document, canvas, framebuffer, or render.