// Add getters and setters for the fields.
for (Entry<String, Field> entry : fields.entrySet()) {
// Getter.
scope.define(entry.getKey(),
new FieldGetter(classObj, entry.getKey(), scope));
// Setter, if the field is mutable ("var" instead of "val").
if (entry.getValue().isMutable()) {
scope.define(Name.makeAssigner(entry.getKey()),
new FieldSetter(classObj, entry.getKey(), entry.getValue(), scope));