code: def x_ticks(self, *ticks):
          
  
          if ticks:
              for tick in ticks:
                  if not is_numeric(tick):
                      raise TypeError("'%s' is not a numeric tick" % str(tick))
              self._x_ticks = tuple(sorted(ticks))
          else:
              if self._x_ticks:
                  return self._x_ticks
              else:
                  return determine_ticks(self.x_lower_limit(), self.x_upper_limit())
docs: The points on the x-axis for which there are markers and grid lines.
  
          There are default ticks, but you can pass values to this method to
          override the defaults. Otherwise the method will return the ticks.
  
          :param \*ticks: if given, these will be chart's x-ticks.
          :rtype: ``tuple``