@return a set containing the child objects associated with this reactor.
This will contain any active instances of: {@link Task} -
created using the {@link #schedule(int, Handler)} method,
{@link Connection} - created using the
{@link #connectionToHost(String, int, Handler)} method,
{@link Acceptor} - created using the
{@link #acceptor(String, int)} method,
{@link #acceptor(String, int, Handler)} method, or
{@link Selectable} - created using the
{@link #selectable()} method.
@return a set containing the child objects associated with this reactor. This will contain any active instances of: {@link Task} - created using the {@link #schedule(int, Handler)} method, {@link Connection} - created using the {@link #connectionToHost(String, int, Handler)} method, {@link Acceptor} - created using the {@link #acceptor(String, int)} method, {@link #acceptor(String, int, Handler)} method, or {@link Selectable} - created using the {@link #selectable()} method.