fn read_constraints_data<F: FieldWitness>(
internal_vars_path: &Path,
rows_rev_path: &Path,
) -> Option<(InternalVars<F>, Vec<Vec<Option<V>>>)>
fn read_constraints_data<F: FieldWitness>(
internal_vars_path: &Path,
rows_rev_path: &Path,
) -> Option<(InternalVars<F>, Vec<Vec<Option<V>>>)>