docs: function setExpiry(key, ms, req) {
    var rval = this.getRawKey(key);
    if(rval === undefined) return 0;
    // expiry is in the past or now, delete immediately
    // but return 1 to indicate the expiry was set
    if(ms <= Date.now()) {
      this.delKey(key, req);
      return 1;
    }
    if(!this._expires[key]) {
      this._ekeys.push(key);
    }
    this._expires[key] = ms;
    rval.e = ms;
    return 1;
  }