tasks.add(command);
    }

    boolean hasNext() {
      return !tasks.isEmpty();
    }

    void runNext() {
      assertTrue("expected at least one task to run", hasNext());
      tasks.remove().run();
    }

    void runAll() {
      while (hasNext()) {
        runNext();
      }
    }
  }

  private FakeExecutor fakePool;
  private SequentialExecutor e;

  @Override

      tasks.add(command);
    }

    boolean hasNext() {
      return !tasks.isEmpty();
    }

    void runNext() {
      assertTrue("expected at least one task to run", hasNext());
      tasks.remove().run();
    }

    void runAll() {
      while (hasNext()) {
        runNext();
      }
    }
  }

  private FakeExecutor fakePool;
  private SequentialExecutor e;

  @Override