Method onFailure

future-java/src/main/java/io/trane/future/Future.java:473–473

Executes the Consumer if this future completes with an exception. @param c the Consumer to be executed. @return a future that completes with the result of this after c is executed, if applicable.

(Consumer<Throwable> c)

   *           executed, if applicable.
   */
  Future<T> onFailure(Consumer<Throwable> c);

  /**
   * Executes the Responder once this future completes. If this future completes