queryInfo(key: String,
index: Integer io): String;
The queryInfo method of the JadeHTTPConnection class retrieves header information associated with an HTTP request.
The key parameter specifies the HTTP header key that is to be retrieved; for example, Accept, Date.
The index parameter enumerates multiple headers with the same key. When calling the function, this parameter is the index of the specified header to return (which is usually zero (0)). When the function returns, this parameter is the index of the next header. If the next index cannot be found, a null value is returned.