code: def _get_axis_dims(self, element):
          
          dims = element.dimensions()[:2]
          if len(dims) == 1:
              return dims + [None, None]
          else:
              return dims + [None]
docs: Returns the dimensions corresponding to each axis.
  
          Should return a list of dimensions or list of lists of
          dimensions, which will be formatted to label the axis
          and to link axes.