private static final long DELAY_MS = 50;
  private static final long ENOUGH_MS = 10000;
  private static final long NOT_ENOUGH_MS = 5;

  private static final String GOOD_CALLABLE_RESULT = "good callable result";
  private static final Callable<String> GOOD_CALLABLE =
      new Callable<String>() {
        @Override
        public String call() throws InterruptedException {
          MILLISECONDS.sleep(DELAY_MS);

In many cases it's not very obvious how environment variables would be useful and applicable right away. But they keep showing up in many different scenarios when you are developing, so it's good to know about them.

 * configurations, and label types for access control.
 *
 * <p>The parser handles the following GSA configuration elements:
 * <ul>
 * <li>Collections with good/bad URL patterns</li>
 * <li>Global parameters including start URLs and filtering rules</li>
 * <li>User agent settings</li>
 * <li>URL pattern matching with regular expressions and contains filters</li>
 * </ul>
 *
 */

 *          <br>
 *          <i>NOTE: This will only be used in very special cases, using a highly controlled vocabulary of possible
 *          values. (Elements like this are why it's a good idea to use the descriptor tools.)</i>
 *      </td>
 *   </tr>
 *   <tr>
 *      <td>phase</td>
 *      <td>defaultPhase = LifecyclePhase.&lt;phase&gt;</td>
 *      <td>No</td>

      // Postponed routes are always tried last. For example, if we have 2 proxies and all the
      // routes for proxy1 should be postponed, we'll move to proxy2. Only after we've exhausted
      // all the good routes will we attempt the postponed routes.
      val proxy = nextProxy()
      for (inetSocketAddress in inetSocketAddresses) {
        val route = Route(address, proxy, inetSocketAddress)

* First, make sure you **understand the problem** that the pull request is trying to solve. It might have a longer discussion in a GitHub Discussion or issue.

* There's also a good chance that the pull request is not actually needed because the problem can be solved in a **different way**. Then you can suggest or ask about that.

### Don't worry about style { #dont-worry-about-style }

 properties file could be used the specify $ so it can be interpolated in
 <developerConnection/> but you couldn't use a properties file to specify the
 version of your project say. Anyway, food for thought to begin with.

 - elements that are critical for pom dissemination
 - those that are used locally by the user like <developerConnection/>

* User configuration

   *
   * <p><b>Note:</b> the overhead of measurement can be more than a microsecond, so it is generally
   * not useful to specify {@link TimeUnit#NANOSECONDS} precision here.
   *
   * <p>It is generally not a good idea to use an ambiguous, unitless {@code long} to represent
   * elapsed time. Therefore, we recommend using {@link #elapsed()} instead, which returns a
   * strongly-typed {@link Duration} instance.
   *

The `name` parameter is **still required** (not *optional*) because it doesn't have a default value. Still, `name` accepts `None` as the value:

```Python
say_hi(name=None)  # This works, None is valid 🎉
```

The good news is, once you are on Python 3.10 you won't have to worry about that, as you will be able to simply use `|` to define unions of types:

{* ../../docs_src/python_types/tutorial009c_py310.py hl[1,4] *}

 *
 * <p>{@code containsKey(k)}, {@code put(k, v)} and {@code remove(k)} are all (expected and
 * amortized) constant time operations. Expected in the hashtable sense (depends on the hash
 * function doing a good job of distributing the elements to the buckets to a distribution not far
 * from uniform), and amortized since some operations can trigger a hash table resize.
 *