System.Security.Permissions.EnvironmentPermission.Intersect C# (CSharp) Method

        public override IPermission Intersect(IPermission target)
        {
            return default(IPermission);
        }

        public override IPermission Intersect(IPermission target)
        {
            // Handle the easy cases first.
            if (target == null)
            {
                return(target);
            }
            else if (!(target is FileIOPermission))
            {
                throw new ArgumentException(_("Arg_PermissionMismatch"));
            }
            else if (((FileIOPermission)target).IsUnrestricted())
            {
                return(Copy());
            }
            else if (IsUnrestricted())
            {
                return(target.Copy());
            }

            // Create a new object and intersect the lists.
            return(new FileIOPermission
                       (PermissionState.None,
                       EnvironmentPermission.Intersect(readList,
                                                       ((FileIOPermission)target).readList),
                       EnvironmentPermission.Intersect(writeList,
                                                       ((FileIOPermission)target).writeList),
                       EnvironmentPermission.Intersect(appendList,
                                                       ((FileIOPermission)target).appendList),
                       EnvironmentPermission.Intersect(discoveryList,
                                                       ((FileIOPermission)target).discoveryList),
                       allLocalFiles & ((FileIOPermission)target).allLocalFiles,
                       allFiles & ((FileIOPermission)target).allFiles));
        }