with 'DX::Role::Predicate';
-# Thing I've ignored for the moment: set key, unset value
-# which for an add should result in an _make_equal style
-# bind-with-add-action I suspect, but I don't have a current use
-# case so punting while I get everything-the-fuck-else done
-
sub _possible_resolution_list {
my ($self, $coll, $key, $value) = @_;
die "First argument to member_at must be a structured value"