private static final ClassNode RULE_FACTORY = new ClassNode(ClosureBackedRuleFactory.class);

    private static final String INPUTS_FIELD_NAME = "__inputs__";
    private static final String RULE_FACTORY_FIELD_NAME = "__rule_factory__";
    private static final Token ASSIGN = new Token(Types.ASSIGN, "=", -1, -1);

    private final String scriptSourceDescription;
    private final URI location;
    private final SourceUnit sourceUnit;