Amazon.TraceListener.DynamoDBTraceListener.ExpandVariables C# (CSharp) Method

        private string ExpandVariables(string value, Document doc)
        {
            string result = value;
            result = Environment.ExpandEnvironmentVariables(result);
            result = variableRegex.Replace(result, match =>
            {
                string key = match.Groups[1].Captures[0].Value;
                if (doc.Contains(key))
                    return doc[key].AsString();
                else
                    return match.Captures[0].Value;
            });
            return result;
        }