public void HandleRequest(IRequestContext context)
{
var commandParams = context.Parameters.ToArray();
var key = _helpers.ToKey(commandParams[0]);
var flags = _helpers.ToFlags(commandParams[1]);
var exptime = _helpers.ToExpiry(commandParams[2]);
var casUnique = ulong.Parse(commandParams[4]);
var result = _cache.Cas(key, flags, exptime, casUnique, context.DataBlock)
? Encoding.ASCII.GetBytes("STORED\r\n")
: Encoding.ASCII.GetBytes("EXISTS\r\n");
context.ResponseStream.WriteAsync(result, 0, result.Length);
}