var myObject = {
  "myprop1":"value",
  "myprop2":"second",
  "myMethod": function(params) {
    this.myprop1 = params[0];
  }
}
var my_instance = new myObject();
script.log(my_instance.myprop1);
my_instance.mymethod(["test","one","two"]);
script.log(my_instance.myprop1);

When adding a value parameter in a module, only the parameter is saved between sessions/projects. If you want to keep the value content, use setAttribute(“saveValueOnly”,false)

var mycontainer = local.values.addContainer("toto");
var myint1 = mycontainer.addIntParameter("myint", "",0,1,65536);
myint1.setAttribute("saveValueOnly",false);