def set_single(self, selected, by_label=None):
        """Deprecated: set the selection of the single item in this control.
        
        Raises ItemCountError if the control does not contain only one item.
        
        by_label argument is ignored, and included only for backwards
        compatibility.

        """
        deprecation(
            "control.items[0].selected = <boolean>")
        if len(self.items) != 1:
            raise ItemCountError(
                "'%s' is not a single-item control" % self.name)
        self._set_selected_state(self.items[0], selected)
dataset/ETHPy150Open deanhiller/databus/webapp/play1.3.x/samples-and-tests/i-am-a-developer/mechanize/ClientForm.py/ListControl.set_single/original