Da wir es als **Wert einem Argument überreichen**, statt es als **Typannotation** zu verwenden, müssen wir `Union` verwenden, selbst in Python 3.10.

Wenn es eine Typannotation gewesen wäre, hätten wir auch den vertikalen Trennstrich verwenden können, wie in:

```Python
some_variable: PlaneItem | CarItem
```

     * Sets the level and returns this.
     *
     * This was deprecated in OkHttp 4.0 in favor of the [level] val. In OkHttp 4.3 it is
     * un-deprecated because Java callers can't chain when assigning Kotlin vals. (The getter remains
     * deprecated).
     */
    fun setLevel(level: Level) =
      apply {
        this.level = level
      }

    @JvmName("-deprecated_level")
    @Deprecated(

       * Static final fields are presumed to be fastest, based on our experience with
       * UnsignedBytesBenchmark. TODO(cpovirk): benchmark this
       */
      /*
       * A CopyOnWriteArraySet<WeakReference> is faster than a newSetFromMap of a MapMaker map with
       * weakKeys() and concurrencyLevel(1), even up to at least 12 cached exception types.
       */

And these models are all sharing a lot of the data and duplicating attribute names and types.

We could do better.

We can declare a `UserBase` model that serves as a base for our other models. And then we can make subclasses of that model that inherit its attributes (type declarations, validation, etc).

     * found, the existing values are replaced.
     */
    operator fun set(
      name: String,
      value: String,
    ) = commonSet(name, value)

    /** Equivalent to `build().get(name)`, but potentially faster. */
    operator fun get(name: String): String? = commonGet(name)

    fun build(): Headers = commonBuild()
  }

  companion object {
    /** Empty headers. */
    @JvmField

   * key/value mapping in the underlying multimap and determine which satisfy the filter. When a
   * live view is <i>not</i> needed, it may be faster to copy the filtered multimap and use the
   * copy.
   *
   * <p><b>Warning:</b> {@code keyPredicate} must be <i>consistent with equals</i>, as documented at

   * key/value mapping in the underlying multimap and determine which satisfy the filter. When a
   * live view is <i>not</i> needed, it may be faster to copy the filtered multimap and use the
   * copy.
   *
   * <p><b>Warning:</b> {@code keyPredicate} must be <i>consistent with equals</i>, as documented at

ent:"\f02a"}.fa-bars:before{content:"\f0c9"}.fa-baseball-ball:before{content:"\f433"}.fa-basketball-ball:before{content:"\f434"}.fa-bath:before{content:"\f2cd"}.fa-battery-empty:before{content:"\f244"}.fa-battery-full:before{content:"\f240"}.fa-battery-half:before{content:"\f242"}.fa-battery-quarter:before{content:"\f243"}.fa-battery-three-quarters:before{content:"\f241"}.fa-battle-net:before{content:"\f835"}.fa-bed:before{content:"\f236"}.fa-beer:before{content:"\f0fc"}.fa-behance:before{conten...

Calling this program outputs:

```
John Doe
```

The function does the following:

* Takes a `first_name` and `last_name`.
* Converts the first letter of each one to upper case with `title()`.
* <abbr title="Puts them together, as one. With the contents of one after the other.">Concatenates</abbr> them with a space in the middle.

{* ../../docs_src/python_types/tutorial001.py hl[2] *}

### Edit it { #edit-it }

import org.jspecify.annotations.Nullable;

/**
 * A wrapper class for unsigned {@code long} values, supporting arithmetic operations.
 *
 * <p>In some cases, when speed is more important than code readability, it may be faster simply to
 * treat primitive {@code long} values as unsigned, using the methods from {@link UnsignedLongs}.
 *
 * <p>See the Guava User Guide article on <a