code: def get_ticks_from_axis_limits(self, multiple=1):
          
          for k in ['b', 'l', 'r']:
              self._ticks[k] = numpy.linspace(
                  self._axis_limits[k][0],
                  self._axis_limits[k][1],
                  self._boundary_scale / float(multiple) + 1
              ).tolist()
docs: Taking self._axis_limits and self._boundary_scale get the scaled
          ticks for all three axes and store them in self._ticks under the
          keys 'b' for bottom, 'l' for left and 'r' for right axes.