def init_layout(self):
        """ Set the checked state after all children have
        been populated.
        
        """
        super(AndroidRadioGroup, self).init_layout()
        d = self.declaration
        w = self.widget
        if d.checked:
            self.set_checked(d.checked)
        else:
            #: Check if any of the children have "checked = True"
            for c in d.children:
                if c.checked:
                    d.checked = c

        w.setOnCheckedChangeListener(w.getId())
        w.onCheckedChanged.connect(self.on_checked_changed)
Set the checked state after all children have
        been populated.