public void testSubmit() throws Exception {
    /*
     * Mostly just tests that TrustedListenableFutureTask are created and run; tests for
     * TrustedListenableFutureTask should ensure that listeners are called correctly.
     */

    TestListeningExecutorService e = new TestListeningExecutorService();

    TestRunnable runnable = new TestRunnable();
    ListenableFuture<?> runnableFuture = e.submit(runnable);

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

## Webhooks steps

The process normally is that **you define** in your code what is the message that you will send, the **body of the request**.

  fun statementStartsAndStops() {
    val called = AtomicBoolean()
    val statement =
      server.apply(
        object : Statement() {
          override fun evaluate() {
            called.set(true)
            server.url("/").toUrl().openConnection().connect()
          }
        },
        Description.EMPTY,
      )
    statement.evaluate()
    assertThat(called.get()).isTrue()
    try {

   * this graph.
   *
   * <p>This is equal to the union of {@link #predecessors(Object)} and {@link #successors(Object)}.
   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *
   * <ul>

t:"Feltets værdi må ikke være kortere end ",max:"max",min:"min",notConfirmed:"Feltværdierne kunne ikke bekræftes",requiredField:"Dette felt er påkrævet",requiredFields:"Du har ikke udfyldt alle påkrævede felter",wrongFileDim:"Forkerte billede dimensioner,",wrongFileSize:"Filen du forsøger at uploade er for stor (max %s)",wrongFileType:"Udelukkende filer at følgedne type er tilladt %s"}})}(a,window)});...

 * resulting in notification could have occurred to an entry being manually removed or replaced, or
 * due to eviction resulting from timed expiration, exceeding a maximum size, or garbage collection.
 *
 * <p>An instance may be called concurrently by multiple threads to process different entries.
 * Implementations of this interface should avoid performing blocking calls or synchronizing on
 * shared resources.
 *

 * instance contains a list of listeners, each with an associated {@code Executor}, and guarantees
 * that every {@code Runnable} that is {@linkplain #add added} will be executed after {@link
 * #execute()} is called. Any {@code Runnable} added after the call to {@code execute} is still
 * guaranteed to execute. There is no guarantee, however, that listeners will be executed in the
 * order that they are added.
 *

 * controls the order in which events are dispatched, while the executor controls how (i.e. on which
 * thread) the subscriber is actually called when an event is dispatched to it.
 *
 * @author Colin Decker
 */
@ElementTypesAreNonnullByDefault
abstract class Dispatcher {

  /**

...Python has a little special syntax for that.

Pass `*`, as the first parameter of the function.

Python won't do anything with that `*`, but it will know that all the following parameters should be called as keyword arguments (key-value pairs), also known as <abbr title="From: K-ey W-ord Arg-uments"><code>kwargs</code></abbr>. Even if they don't have a default value.

```Python hl_lines="7"

## `PATH` Environment Variable

There is a **special** environment variable called **`PATH`** that is used by the operating systems (Linux, macOS, Windows) to find programs to run.