controller stack motivation

contract MyTargetInterface {
    function func1(int arg1, int arg2) returns (int ret);
    function func2(bytes32 arg1) returns (bytes32 ret);
}

contract MyActions is DSControlledAction, MyTargetInterface {
    function MyActions( DSController env ) DSControlledAction( env ) {}
    function func1(int arg1, int arg2) returns (int ret) {
        setReturn(bytes32(arg1 + arg2));
        return 0; // doesn't matter
    }
    function func2(bytes32 adder_location) returns (bytes32 ret) {
        // Dev doesn't care it's actually also the same controller/action objects - that's an implementation detail
        var adder = MyTargetInterface(address(getEnv(adder_location)));
        setReturn(bytes32(adder.func1(1, 2)));
    }
}

contract DSControllerTest is Test {
    DSController controller;
    function setUp() {
        controller = new DSController();
        controller.set("adder", controller);
        DSControlledAction actions = DSControlledAction(new MyActions(controller));
        var sig1 = bytes4(sha3("func1(int256,int256)"));
        var sig2 = bytes4(sha3("func2(int256,int256)"));
        controller._ds_pushAction(sig1, actions, 0, true);
        controller._ds_pushAction(sig2, actions, 0, true);
    }

    function testBasic() {
        assertEq(3, MyTargetInterface(controller).func2());
    }
}