constructor(modelClass, clauses, opts) {
        Object.assign(this, {
            modelClass,
            clauses: clauses || [],
        });

        this._opts = opts;
    }
Creates a QuerySet. The constructor is mainly for internal use;
You should access QuerySet instances from {@link Model}.

@param  {Model} modelClass - the model class of objects in this QuerySet.
@param  {any[]} clauses - query clauses needed to evaluate the set.
@param {Object} [opts] - additional options