public static void Main()
Console.WriteLine("Hello World");
string s = "{\"owa_1\":null}";
if (s.Contains("owa_1\":null"))
Console.WriteLine("that matched");
if (s.Contains(@"owa_1"":null"))
Console.WriteLine("that matched too");
if (s.Contains(@"owa_1\"":null"))
Console.WriteLine("that matched three");