/// Debug-assert that there is exactly one `Root` expression, and it is the model's top-level root.
"Model from '{origin}' should contain exactly one Root expression at top-level, found {total_root_count}"
/// Debug-assert that there is exactly one `Root` expression, and it is the model's top-level root.
let mut pending_tables: Vec<SymbolTablePtr> = vec![model.symbols_ptr_unchecked().clone()];