import run_tests

def traffic_light() -> Obj:

    is_green = False
    timeout = 0

    def dispatch( what: str, *args: Any ) -> Any:
        nonlocal is_green, timeout

        if what == 'is_green':
            return is_green
        if what == 'set_green':
            is_green = True
        if what == 'set_red':
            timeout = 5
        if what == 'tick':
            if timeout > 0:
                timeout -= 1
                if timeout == 0:
                    is_green = False

    return dispatch

def button( pedestrian_light: Obj, vehicle_light: Obj ) -> Obj:

    timeout = 0
    to_green = True

    def dispatch( what: str, *args: Any ) -> Any:
        nonlocal to_green, timeout

        if what == 'push':
            vehicle_light( 'set_red' )

        if what == 'tick':
            if not vehicle_light( 'is_green' ) and \
               not pedestrian_light( 'is_green' ):

                if to_green:
                    pedestrian_light( 'set_green' )
                    timeout = 20
                else:
                    vehicle_light( 'set_green' )
                    to_green = True

            if timeout > 0:
                timeout -= 1
                if timeout == 0:
                    pedestrian_light( 'set_red' )
                    to_green = False

    return dispatch