has(scope, index, validate) {
    let valid = validate;
    /** @type {number|null} */
    let idx;
    if (typeof index === 'function') {
      valid = /** @type {HasValidationCallback} */ (index);
      idx = null;
    } else {
      idx = index;
    }
    if (this.hasIPinBuffer(scope, idx, valid)) { return true; }
    if (this.hasIIP(idx, valid)) { return true; }
    return false;
  }
Returns true if port contains packet(s) matching the validator
@param {string|null} scope
@param {number|null|HasValidationCallback} index
@param {HasValidationCallback} [validate]