code: function evalsha(req, res, sha, args) {
    this.spawn();
    this.reply(req, res, this._limit);
    // need to coerce buffers for the moment
    args = args.map(function(a) {
      if(a instanceof Buffer) return a.toString();
      return a;
    })
    this.ps.send({event: 'evalsha', sha: sha, args: args});
  }
docs: Evaluate a script by sha checksum.