function backwardsManyToOneDescriptor(
    declaredFieldName,
    declaredFromModelName
) {
    return {
        get() {
            const {
                session: { [declaredFromModelName]: DeclaredFromModel },
            } = this.getClass();

            return DeclaredFromModel.filter({
                [declaredFieldName]: this.getId(),
            });
        },
        set() {
            throw new Error("Can't mutate a reverse many-to-one relation.");
        },
    };
}
The backwards direction of a n-to-1 relationship (i.e. 1-to-n),
meaning this will return an a collection (`QuerySet`) of model instances.

An example would be `author.books` referencing all instances of
the `Book` model that reference the author using `fk()`.