static StringBuilder buildCanonicalizedHeaders(IDictionary<string, string> headers)
{
// Create the canonicalized header string to return.
StringBuilder sb = new StringBuilder(256);
foreach (string key in headers.Keys.OrderBy(x => x, StringComparer.OrdinalIgnoreCase))
{
var lowerKey = key.ToLower(CultureInfo.InvariantCulture);
if (!lowerKey.StartsWith("x-amz-", StringComparison.Ordinal))
continue;
sb.Append(String.Concat(lowerKey, ":", headers[key], "\n"));
}
return sb;
}
}