///

```Python hl_lines="2  5-8  11"
{!> ../../docs_src/settings/tutorial001_pv1.py!}
```

////

/// tip

If you want something quick to copy and paste, don't use this example, use the last one below.

///

 *     .build();
 * ```
 *
 * ## Force a Cache Response
 *
 * Sometimes you'll want to show resources if they are available immediately, but not otherwise.
 * This can be used so your application can show *something* while waiting for the latest data to be
 * downloaded. To restrict a request to locally-cached resources, add the `only-if-cached`
 * directive:
 *
 * ```java
 * Request request = new Request.Builder()

By validating the data with Pydantic we can make sure that we have, for example, exactly a `list` of `str` with the scopes and a `str` with the `username`.

Instead of, for example, a `dict`, or something else, as it could break the application at some point later, making it a security risk.

We also verify that we have a user with that username, and if not, we raise that same exception we created before.

These particular phases in a plugin’s lifecycle can probably be generalized to all plugins so could be something implemented in all plugins. Here we could have the descriptor either point to methods for each of these phases to execute or we could create a lifecycle in Plexus for these phases.

            To properly test this, you need to remove existing toolchains:
            rm -rf ~/.m2/jdks/ ~/.m2/toolchains.xml
            (But don't run that if you have put something into ~/.m2/toolchains.xml yourself.)
            -->
            <execution>
              <id>download-11</id>
              <goals>
                <goal>toolchain</goal>
              </goals>

            To properly test this, you need to remove existing toolchains:
            rm -rf ~/.m2/jdks/ ~/.m2/toolchains.xml
            (But don't run that if you have put something into ~/.m2/toolchains.xml yourself.)
            -->
            <execution>
              <id>download-11</id>
              <goals>
                <goal>toolchain</goal>
              </goals>

 *   <li><b>Convenience methods:</b> These are implementations of common operations that are
 *       typically implemented by opening a reader using one of the methods in the first category,
 *       doing something and finally closing the reader that was opened.
 * </ul>
 *
 * <p>Several methods in this class, such as {@link #readLines()}, break the contents of the source

   */
  protected final class MultiExceptionListIterator implements ListIterator<E> {
    // TODO: track seen elements when order isn't guaranteed
    // TODO: verify contents afterward
    // TODO: something shiny and new instead of Stack
    // TODO: test whether null is supported (create a Feature)
    /**
     * The elements to be returned by future calls to {@code next()}, with the first at the top of
     * the stack.

@GwtCompatible(emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization
@ElementTypesAreNonnullByDefault
// TODO(kevinb): I think we should push everything down to "BaseImmutableCollection" or something,
// just to do everything we can to emphasize the "practically an interface" nature of this class.
public abstract class ImmutableCollection<E> extends AbstractCollection<E> implements Serializable {
  /*

 *
 * <h3>Comparison to alternatives</h3>
 *
 * <p><b>Note:</b> In some cases the differences explained below can be subtle. When it's unclear
 * which approach to use, <b>don't worry</b> too much about it; just pick something that seems
 * reasonable and it will be fine.
 *
 * <ul>
 *   <li>If checking whether the <i>caller</i> has violated your method or constructor's contract