defer xioutil.SafeClose(keyCh)

		retryTicker := time.NewTicker(retryInterval)
		defer retryTicker.Stop()

		for {
			for _, key := range store.List() {
				select {
				case keyCh <- key:
				// Get next key.
				case <-doneCh:
					return
				}
			}

			select {
			case <-retryTicker.C:
			case <-doneCh:
				return
			}
		}
	}()

	return keyCh
}

This would be typical after a user initiates a force refresh by a pull to refresh type action.

```java
    val urlIterator = cache.urls()
    while (urlIterator.hasNext()) {
      if (urlIterator.next().startsWith("https://www.google.com/")) {
        urlIterator.remove()
      }
    }
```

### Troubleshooting

1. Valid cacheable responses are not being cached

  interface Callback {
    fun onEvent(
      id: String?,
      type: String?,
      data: String,
    )

    fun onRetryChange(timeMs: Long)
  }

  /**
   * Process the next event. This will result in a single call to [Callback.onEvent] *unless* the
   * data section was empty. Any number of calls to [Callback.onRetryChange] may occur while
   * processing an event.
   *

      true
    } else {
      scheduleCloser()
      false
    }
  }

  fun evictAll() {
    val i = connections.iterator()
    while (i.hasNext()) {
      val connection = i.next()
      val socketToClose =
        connection.withLock {
          if (connection.calls.isEmpty()) {
            i.remove()
            connection.noNewExchanges = true

And it should have an `access_token`, with a string containing our access token.

For this simple example, we are going to just be completely insecure and return the same `username` as the token.

/// tip

In the next chapter, you will see a real secure implementation, with password hashing and <abbr title="JSON Web Tokens">JWT</abbr> tokens.

But for now, let's focus on the specific details we need.

///

//// tab | Python 3.10+

   * high 32 bits of each long is the "prev" pointer, whereas the low 32 bits is the "succ" pointer
   * (pointing to the next entry in the linked list). The pointers in [size(), entries.length) are
   * all "null" (UNSET).
   *
   * <p>A node with "prev" pointer equal to {@code ENDPOINT} is the first node in the linked list,
   * and a node with "next" pointer equal to {@code ENDPOINT} is the last node.
   */

      resetContainer(mapEntry(k0(), v0()), mapEntry(k0(), v1()), mapEntry(k0(), v0()));
      List<V> expectedValues = copyToList(values);

      Entry<K, Collection<V>> asMapEntry = multimap().asMap().entrySet().iterator().next();
      List<V> asMapValue = (List<V>) asMapEntry.getValue();
      asMapValue.remove(i);
      expectedValues.remove(i);

      assertGet(k0(), expectedValues);
    }
  }

        ConcurrentModificationException.class,
        () -> {
          Iterator<E> iterator = collection.iterator();
          assertTrue(collection.removeIf(Predicate.isEqual(samples.e0())));
          iterator.next();
        });
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRemoveIf_unsupportedEmptyCollection() {
    try {
      assertFalse(

            off = in.readDirect(buf, 0, buf.length);
        }

        if (buf[0] != 5 && buf[1] != 0)
            throw new IOException("Unexpected DCERPC PDU header");

        flags = buf[3] & 0xFF;
        // next read is start of new frag
        isStart = (flags & DCERPC_LAST_FRAG) == DCERPC_LAST_FRAG;

        length = Encdec.dec_uint16le(buf, 8);
        if (length > max_recv)

         * the association between the artifacts of the same project.
         */
        for (Iterator<? extends Metadata> it = metadatas.iterator(); it.hasNext(); ) {
            Metadata metadata = it.next();
            if (metadata instanceof VersionsMetadata) {
                it.remove();
                VersionsMetadata versionsMetadata = (VersionsMetadata) metadata;