code: def enable_autocenter(self, option):
          
          option = option.lower()
          assert(option in self.autocenter_options), \
              ImageViewError("Bad autocenter option '%s': must be one of %s" % (
                  str(self.autocenter_options)))
          self.t_.set(autocenter=option)
docs: Set ``autocenter`` behavior.
  
          Parameters
          ----------
          option : {'on', 'override', 'once', 'off'}
              Option for auto-center behavior. A list of acceptable options can
              also be obtained by :meth:`get_autocenter_options`.
  
          Raises
          ------
          ginga.ImageView.ImageViewError
              Invalid option.