For instance Convert.ToString(string) doesn't do anything and can be annotated as: ```cs [ContractAnnotation("s: notnull => notnull; s: null => null")] public static string ToString(string s); // { return s; } ``` Similar to other methods of [Convert](https://docs.microsoft.com/en-us/dotnet/api/system.convert?view=netframework-4.7.2).
For instance Convert.ToString(string) doesn't do anything and can be annotated as:
Similar to other methods of Convert.