if (seenExceptionsLocal == null) {
      // TODO(cpovirk): Should we use a simpler (presumably cheaper) data structure?
      /*
       * Using weak references here could let us release exceptions earlier, but:
       *
       * 1. On Android, querying a WeakReference blocks if the GC is doing an otherwise-concurrent
       * pass.
       *

        ArtifactResolutionResult result = resolve(request);

        // We have collected all the problems so let's mimic the way the old code worked and just blow up right here.
        // That's right lets just let it rip right here and send a big incomprehensible blob of text at unsuspecting
        // users. Bad dog!

        resolutionErrorHandler.throwErrors(request, result);

        return result;
    }

          Him, and ourselves, and it.

        Don't let him know she liked them best,
          For this must ever be
        A secret, kept from all the rest,
          Between yourself and me.'

  `That's the most important piece of evidence we've heard yet,'
said the King, rubbing his hands; `so now let the jury--'

  `If any one of them can explain it,' said Alice, (she had

                  CollectionFeature.RESTRICTS_ELEMENTS,
                  ListFeature.SUPPORTS_SET)
              .createTestSuite());
    }
    return suite;
  }

  // Test generators.  To let the GWT test suite generator access them, they need to be
  // public named classes with a public default constructor.

  public static final class FloatsAsListGenerator extends TestFloatListGenerator {
    @Override

                  CollectionFeature.RESTRICTS_ELEMENTS,
                  ListFeature.SUPPORTS_SET)
              .createTestSuite());
    }
    return suite;
  }

  // Test generators.  To let the GWT test suite generator access them, they need to be
  // public named classes with a public default constructor.

  public static final class FloatsAsListGenerator extends TestFloatListGenerator {
    @Override

                  CollectionFeature.RESTRICTS_ELEMENTS,
                  ListFeature.SUPPORTS_SET)
              .createTestSuite());
    }
    return suite;
  }

  // Test generators.  To let the GWT test suite generator access them, they need to be
  // public named classes with a public default constructor.

  public static final class IntsAsListGenerator extends TestIntegerListGenerator {
    @Override

   */
  @SuppressWarnings("unchecked")
  public static <T extends @Nullable Object> Collector<T, ?, T> onlyElement() {
    return (Collector) ONLY_ELEMENT;
  }

  /**
   * This atrocity is here to let us report several of the elements in the stream if there were more
   * than one, not just two.
   */
  @SuppressWarnings("EmptyList") // ImmutableList doesn't support nullable element types

          val coordinatorTask = waitingCoordinatorTask ?: error("no coordinator waiting")
          currentTask = coordinatorTask
          taskRunner.notifyAll()
        }
      }

    // Let the coordinator process its interruption.
    runTasks()
  }

  /** Ask a single task to proceed. Used by the test thread only. */
  fun runNextTask() {
    taskRunner.assertLockNotHeld()

Then, the browser will send an HTTP `OPTIONS` request to the `:80`-backend, and if the backend sends the appropriate headers authorizing the communication from this different origin (`http://localhost:8080`) then the `:8080`-browser will let the JavaScript in the frontend send its request to the `:80`-backend.

To achieve this, the `:80`-backend must have a list of "allowed origins".

       * running under Jelly Bean or higher. But it seems safest to check.
       */
      if (version < jellyBean) {
        return new ThrowingCreator();
      }

      // Don't merge these catch() blocks, let alone use ReflectiveOperationException directly:
      // b/65343391
    } catch (NoSuchFieldException e) {
      // The JELLY_BEAN field doesn't exist because we're running on a version before Jelly Bean :)