Flag tests (for revocation)

Test.cs

using System;
using System.Linq;

public class Program
{
  [Flags]
  public enum E
  {
    None = 0,

    A = 1,
    B = 2,
    C = 4,
    D = 8
  }

  public static void Main()
  {
    // ONLY
    Test(new[] { E.None });
    Test(new[] { E.None, E.B });
    Test(new[] { E.None, E.C });    
    Test(new[] { E.None, E.B, E.C });
    Test(new[] { E.B });
    Test(new[] { E.C });    
    Test(new[] { E.B, E.C });
    Test(new[] { E.B | E.C });
    
    Console.WriteLine("Contains other");
    
    // Other
    Test(new[] { E.A });
    Test(new[] { E.A, E.B });
    Test(new[] { E.A | E.B });
    Test(new[] { E.None, E.B, E.A });
    Test(new[] { E.None, E.B, E.A | E.B });
  }

  public static void Test(E[] flags)
  {
    var unknown = E.B | E.C;

    if (flags.Any(f => (f & ~unknown) != E.None))
    {
      Console.WriteLine($"Flags {string.Join(", ", flags)} contain something other than {unknown}");
    }
    else
    {
      Console.WriteLine($"Flags {string.Join(", ", flags)} are ONLY {unknown}, or {nameof(E.None)}");
    }
  }
}