Method between

packages/filter/src/query.ts:433–437

* Add a `between` condition * @param key - Property name * @param val1 - Property value lower bound * @param val2 - Property value upper bound

(key: K, val1: MT[K], val2: MT[K])

   * @param val2 - Property value upper bound
   */
  between<K extends KeyOf<MT>>(key: K, val1: MT[K], val2: MT[K]): this {
    const w: Where<MT> = {};
    w[key] = {between: [val1, val2]};
    return this.add(w);
  }

  /**
   * Add a `exists` condition