Write Mocha tests to verify the functionality of the following JS code:

class SortedList {
    constructor() {
        this.list = [];
    }
 
    add(element) {
        this.list.push(element);
        this.sort();
    }
 
    remove(index) {
        this.vrfyRange(index);
        this.list.splice(index, 1);
    }
 
    get(index) {
        this.vrfyRange(index);
        return this.list[index];
    }
 
    vrfyRange(index) {
        if (this.list.length == 0) throw new Error("Collection is empty.");
        if (index < 0 || index >= this.list.length) throw new Error("Index was outside the bounds of the collection.");
    }
 
    sort() {
        this.list.sort((a, b) => a - b);
    }
 
    get size() {
        return this.list.length;
    }
}

Your tests will be supplied with a class named SortedList. It needs to meet the following requirements:

• Maintains a collection of numeric elements
• Has an add(element) function, which adds a new element to the collection
• Has a remove(index) function, which removes the element at position index
• Has a get(index) function, which return the value of the element at position index
• Keeps the elements of the collection sorted in ascending order at all times
• Throws an error if the functions get() and remove() are supplied with an invalid index (negative or outside the collection) or if the collection is empty
• Has a size() property getter, which returns the number of elements inside the collection