* is set to {@code null}.
   *
   * <p>Like the {@link #toArray()} method, this method acts as bridge between array-based and
   * collection-based APIs. Further, this method allows precise control over the runtime type of the
   * output array, and may, under certain circumstances, be used to save allocation costs.
   *

│   │   └── users.py
│   └── internal
│       ├── __init__.py
│       └── admin.py
```

/// tip

There are several `__init__.py` files: one in each directory or subdirectory.

This is what allows importing code from one file into another.

For example, in `app/main.py` you could have a line like:

```
from app.routers import items
```

///

 * the reference is "absent"); it is never said to "contain {@code null}".
 *
 * <p>A non-null {@code Optional<T>} reference can be used as a replacement for a nullable {@code T}
 * reference. It allows you to represent "a {@code T} that must be present" and a "a {@code T} that
 * might be absent" as two distinct types in your program, which can aid clarity.
 *
 * <p>Some uses of this class include
 *
 * <ul>

 * @since 16.0
 */
@GwtCompatible
public abstract class MultimapBuilder<K0 extends @Nullable Object, V0 extends @Nullable Object> {
  /*
   * Leaving K and V as upper bounds rather than the actual key and value types allows type
   * parameters to be left implicit more often. CacheBuilder uses the same technique.
   */

  private MultimapBuilder() {}

  private static final int DEFAULT_EXPECTED_KEYS = 8;

///

## Type Hints with Metadata Annotations { #type-hints-with-metadata-annotations }

Python also has a feature that allows putting **additional <abbr title="Data about the data, in this case, information about the type, e.g. a description.">metadata</abbr>** in these type hints using `Annotated`.

       * parameters. If it were statically checked, the checker would still be OK with it, since
       * we're copying into a `contents` array whose type allows it to contain nulls. Still, it's
       * worth noting that we promise not to put nulls into the array in the first `size` elements.
       * We uphold that promise here because our callers promise that `elements` will not contain

   * @throws IndexOutOfBoundsException if either index is negative, {@code rowIndex} is greater than
   *     or equal to the number of allowed row keys, or {@code columnIndex} is greater than or equal
   *     to the number of allowed column keys
   */
  public @Nullable V at(int rowIndex, int columnIndex) {
    // In GWT array access never throws IndexOutOfBoundsException.

        return lifecycles.computeIfAbsent(project.getId(), k -> new ArrayDeque<>());
    }

    /**
     * Copy packaged and attached artifacts from this project to the
     * project local repository.
     * This allows a subsequent build to resume while still being able
     * to locate attached artifacts.
     *
     * @param project the project to copy artifacts from
     */

(Alpha), allowing you to specify application-level metrics and thresholds to
trigger scaling up and down the number of pods in your application.
  * <strong>New GUI</strong> (dashboard) allows you to get started quickly and enables the same
functionality found in the CLI as a more approachable and discoverable way of
interacting with the system. Note: the GUI is enabled by default in 1.2 clusters.

     * index. This constructor is optimized so that it starts at either the head or the tail,
     * depending on which is closer to the specified index. This allows adds to the tail to be done
     * in constant time.
     *
     * @throws IndexOutOfBoundsException if index is invalid
     */
    ValueForKeyIterator(@ParametricNullness K key, int index) {