Used in this article: https://medium.com/@bgoetzmann/modèle-de-conception-commande-en-langage-groovy-9bea26b47d6

MacroCartCommand.groovy

class MacroCartCommand implements CartCommand {
    def commands = []
    
    MacroCartCommand leftShift(CartCommand command) {
        commands << command
        this
    }

    void setReceiver(Cart cart) {
        commands*.cart = cart
    }

    def execute() {
        commands*.execute()
    }
}

def macroCommand = new MacroCartCommand()
macroCommand << command1 << command2 << command3

def newCart = new Cart()

macroCommand.receiver = newCart
macroCommand.execute()

assert newCart.items.keySet() == ['Item2'] as Set