System.Security.Permissions.SecurityPermission.ToXml C# (CSharp) Method

        public override SecurityElement ToXml()
        {
            return default(SecurityElement);
        }

		public void AddToPermissionSet ()
		{
			PolicyStatement ps = new PolicyStatement (null);
			Assert.AreEqual (Empty.ToString (), ps.PermissionSet.ToString (), "Empty");

			SecurityPermission sp = new SecurityPermission (SecurityPermissionFlag.Execution);
			IPermission p = ps.PermissionSet.AddPermission (sp);
			Assert.AreEqual (sp.ToXml ().ToString (), p.ToXml ().ToString (), "AddPermission");

			// but nothing was added
			Assert.AreEqual (Empty.ToString (), ps.PermissionSet.ToString (), "Still Empty");
			// and (strangely) it's not considered a read-only permission set 
			// as this property is always false for PermissionSet
			Assert.IsFalse (ps.PermissionSet.IsReadOnly, "IsReadOnly");
		}