Sets whether or not this toolbar is in a collapsed state.
        
        :return     <bool> changed

def setCollapsed(self, state):
        """
        Sets whether or not this toolbar is in a collapsed state.
        
        :return     <bool> changed
        """
        if state == self._collapsed:
            return False
        
        self._collapsed = state
        self.refreshButton()
        
        if not self.signalsBlocked():
            self.collapseToggled.emit(state)
        
        return True