default Stream<StreamSupplierComponent> sourceStreamSupplierComponents() {
        return Stream.empty();
    }
Creates and returns a new Stream of underlying {@code StreamSupplierComponent} objects
that provides data to this {@code StreamSupplierComponent}. If no such component exists
(i.e. the component draws data only from external sources like databases or files) an
empty stream is returned.

@return a new Stream of underlying {@code StreamSupplierComponent} objects
that provides data to this {@code StreamSupplierComponent}
runtime-parent/runtime-core/src/main/java/com/speedment/runtime/core/component/StreamSupplierComponent.java