docs: function delKey(key, req) {
    var rval = this.getRawKey(key);
    if(rval !== undefined) {
  
      // clean expires reference
      this.delExpiry(key, req);
  
      delete this._data[key];
      this._keys.splice(ArrayIndex.indexOf(key, this._keys), 1);
      return 1;
    }
    return 0;
  }