Multiple line code transformations using MTRC

I am trying to put code such as

``` javascript
class MonadObject {
constructor(ob) {

this.x = mobservable.makeReactive(ob);

this.bnd = (func, ...args) => {
return func(this.x, ...args);
};

this.ret = w => {
Object.assign(this.x, w);
return this;
}
}
}
```

on a web page. I don't know how to put the whole snippet in quotes, other than concatenating line by line. Here is what I see in the Chrome browser console log after I insert the code in a running app:

code: "class Monad {↵ constructor(z) {↵↵ this.x = mobservable.makeReactive(z);↵↵ this.bnd = (func, ...args) => {↵ return func(this.x(), ...args);↵ };↵↵ this.ret = a => {↵ this.x(a);↵ return this;↵ };↵ }↵};"

Firefox shows the same thing I get when I put the Chrome text in markdown, namely:

``` javascript
class MonadObject { constructor(ob) { this.x = mobservable.makeReactive(ob); this.bnd = (func, ...args) => { return func(this.x, ...args); }; this.ret = w => { Object.assign(this.x, w); return this; } }}
```

I might soon have use for the full functionality of "markdown-to-react-components", but right now I don't need anything dynamic or interactive. I just want "this.state.content = ?" where ? never changes. I am trying "MTRC(x).tree, but I don't know how to substitute my "Monad" code for "x".

The examples show only single-line arguments for MTRC. If there is a way to use it with multiple lines of text, I think that would be of general interest. Or maybe I have a blind spot and everybody else already knows how to handle this.

Thanks to anybody who can point me in the right direction. This is great software and I feel confident that it is quite capable of handling my use case. But how?