example

function main () {
    computer.checkEmail();
}

computer = {
    checkEmail: function () {
        server.sendUnsentEmail();

        newEmail = server.newEmail();

        if (newEmail) {
            server.downloadEmail();
        }

        server.deleteOldEmail();
    }
}

server = {
    sendUnsentEmail: function () {},
    newEmail: function () {
        response = true;
        return response;
    },
    downloadEmail: function () {},
    deleteOldEmail: function () {},
}