I’m trying to build named constraints over arbitrary dimensions using @constraintref e.g.

```
function build_empty_constraint(constraint_dimensions)
# e.g. constraint_dimensions = [1:2, 3:4]
@constraintref some_constraint[i for i in constraint_dimensions]
return None
end
build_empty_constraint([1:2, 3:4])
```

I assume this would be the same as saying `@constraintref some_constraint[1:2, 3:4]`

But I get the error:

```
Syntax error: Expected some_constraint[i for i = constraint_dimensions] to be of form var[...]
```

Is there any way to avoid this?