'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.'

def set_single(self, selected, by_label=None):

    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)
