code: def limit_x(
          self,
          limit_lower = None, # float
          limit_upper = None  # float
          ):
  
          
  
          if limit_lower is None and limit_upper is None:
              return self._limit_x
          elif hasattr(limit_lower, "__iter__"):
              self._limit_x = limit_lower[:2]
          else:
              self._limit_x = [limit_lower, limit_upper]
          if self._limit_x[0] == self._limit_x[1]:
              self._limit_x[1] += 1
          self._limit_x[0] -= self.mod_x
          self._limit_x[1] += self.mod_x
docs: get or set x limits of the current axes
  
          x_min, x_max = limit_x() # return the current limit_x
          limit_x(x_min, x_max)    # set the limit_x to x_min, x_max