types.add(analyzer.type(b.element));
}
// Unify the tuple type with any previous tuple type and update
// its variant.
final TupleT t1 = ast.toTuple(name);
final TupleT t2 = new TupleT(name, types);
final boolean fresh = (null == t1.getTypes());
if (fresh && ! runtime.test("optionVariant")) {
ast.add(t1, ast.toVariant("Node", false));
}