Annotates methods of a Module to add items to a Multibinder. The method's return type and binding annotation determines what Set this will contribute to. For example,

@ProvidesIntoSet
@Named("urls")
String provideFooUrl(FooManager fm) { return fm.getUrl(); }

@ProvidesIntoSet
@Named("urls")
String provideBarUrl(BarManager bm) { return bm.getUrl(); }

will add two items to the @Named("urls") Set<String> set. The items are bound as providers and will be evaluated at injection time.