namespace System.Collections.Immutable { internal static class Requires { public static void NotNull<T>(T value, string parameterName) where T : class; public static T NotNullPassthrough<T>(T value, string parameterName) where T : class; public static void NotNullAllowStructs<T>(T value, string parameterName); public static void Range(bool condition, string parameterName, string message = null); public static void FailRange(string parameterName, string message = null); public static void Argument(bool condition, string parameterName, string message); public static void Argument(bool condition); public static void FailObjectDisposed<TDisposed>(TDisposed disposed); } }