final Runnable runnable;
      final Executor executor;

      RunnableExecutorPair(Runnable runnable, Executor executor) {
        this.runnable = runnable;
        this.executor = executor;
      }

      void execute() {
        try {
          executor.execute(runnable);
        } catch (RuntimeException e) {
          log.log(
              Level.SEVERE,
              "RuntimeException while executing runnable "

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

```

////

These dependencies will be executed/solved the same way as normal dependencies. But their value (if they return any) won't be passed to your *path operation function*.

/// tip

Some editors check for unused function parameters, and show them as errors.

Using these `dependencies` in the *path operation decorator* you can make sure they are executed while avoiding editor/tooling errors.

            if (!p.isAlive()) {
                return;
            }

            executed.set(true);

            if (logger.isDebugEnabled()) {
                logger.debug("Interrupting a stream thread.");
            }
            ist.interrupt();

            CommonPoolUtil.execute(() -> {
                try {
                    CloseableUtil.closeQuietly(p.getInputStream());

```Python hl_lines="1  15"
{!../../docs_src/debugging/tutorial001.py!}
```

### About `__name__ == "__main__"`

The main purpose of the `__name__ == "__main__"` is to have some code that is executed when your file is called with:

<div class="termy">

```console
$ python myapp.py
```

</div>

but is not called when another file imports it, like in:

```Python
from myapp import app
```

    // the underlying supplier hasn't executed yet
    assertEquals(0, countingSupplier.calls);

    assertEquals(10, (int) memoizedSupplier.get());

    // now it has
    assertEquals(1, countingSupplier.calls);

    assertEquals(10, (int) memoizedSupplier.get());

    // it still should only have executed once due to memoization
    assertEquals(1, countingSupplier.calls);
  }

    // the underlying supplier hasn't executed yet
    assertEquals(0, countingSupplier.calls);

    assertEquals(10, (int) memoizedSupplier.get());

    // now it has
    assertEquals(1, countingSupplier.calls);

    assertEquals(10, (int) memoizedSupplier.get());

    // it still should only have executed once due to memoization
    assertEquals(1, countingSupplier.calls);
  }

     * does your mojo requires a project to be executed?
     * @return requires a project
     */
    boolean projectRequired() default true;

    /**
     * if the Mojo uses the Maven project and its subprojects.
     * @return uses the Maven project and its subprojects
     */
    boolean aggregator() default false;

    /**
     * does this Mojo need to be online to be executed?
     * @return need to be online
     */

Only the code prior to and including the `yield` statement is executed before creating a response:

```Python hl_lines="2-4"
{!../../docs_src/dependencies/tutorial007.py!}
```

The yielded value is what is injected into *path operations* and other dependencies:

```Python hl_lines="4"
{!../../docs_src/dependencies/tutorial007.py!}
```

The code following the `yield` statement is executed after the response has been delivered:

  }

  // Takes a description of a single operation being executed on the
  // ParallelDevice, and in turn runs one operation per component device with
  // its corresponding inputs from the input ParallelTensors. Wraps the
  // resulting per-device and per-output TFE_TensorHandles into one
  // ParallelTensor per output of the original operation.
  //
  // Attributes are forwarded to executed operations unmodified.
  //