*       MoreExecutors.listeningDecorator}.
 *   <li>If you manually call {@link java.util.concurrent.FutureTask#set} or a similar method,
 *       create a {@link SettableFuture} instead. (If your needs are more complex, you may prefer
 *       {@link AbstractFuture}.)
 * </ul>
 *
 * <p><b>Test doubles</b>: If you need a {@code ListenableFuture} for your test, try a {@link

 *       MoreExecutors.listeningDecorator}.
 *   <li>If you manually call {@link java.util.concurrent.FutureTask#set} or a similar method,
 *       create a {@link SettableFuture} instead. (If your needs are more complex, you may prefer
 *       {@link AbstractFuture}.)
 * </ul>
 *
 * <p><b>Test doubles</b>: If you need a {@code ListenableFuture} for your test, try a {@link

 * <ul>
 *   <li>{@code merge} (default): Merges attributes and values</li>
 *   <li>{@code override}: Completely replaces the element</li>
 *   <li>{@code remove}: Removes the element</li>
 * </ul>
 *
 * <p>For complex XML structures, combining can also be done based on:</p>
 * <ul>
 *   <li>ID: Using the {@code combine.id} attribute</li>
 *   <li>Keys: Using the {@code combine.keys} attribute with comma-separated key names</li>
 * </ul>
 *

But before that, handling asynchronous code was quite more complex and difficult.

In previous versions of Python, you could have used threads or <a href="https://www.gevent.org/" class="external-link" target="_blank">Gevent</a>. But the code is way more complex to understand, debug, and think about.

> What’s the history of this project? It seems to have come from nowhere to awesome in a few weeks [...]

Here's a little bit of that history.

## Alternatives { #alternatives }

I have been creating APIs with complex requirements for several years (Machine Learning, distributed systems, asynchronous jobs, NoSQL databases, etc), leading several teams of developers.

As part of that, I needed to investigate, test and use many alternatives.

        assertEquals(16L, MemoryUtil.sizeOf(Boolean.TRUE));
        assertEquals(16L, MemoryUtil.sizeOf(Boolean.FALSE));
    }

    public void test_sizeOf_complexNestedStructures() {
        // Complex nested structure
        Map<String, Object> complexMap = new HashMap<>();
        complexMap.put("strings", Arrays.asList("test1", "test2"));
        complexMap.put("numbers", Arrays.asList(1, 2, 3));

        // Test with null permissions
        user = new TestFessUser("testuser", new String[] {}, new String[] {}, null);
        assertNull(user.getPermissions());

        // Test with complex permission strings
        permissions = new String[] { "admin:*", "user:read", "document:write:123" };
        user = new TestFessUser("testuser", new String[] {}, new String[] {}, permissions);

To send data, you should use one of: `POST` (the more common), `PUT`, `DELETE` or `PATCH`.

Sending a body with a `GET` request has an undefined behavior in the specifications, nevertheless, it is supported by FastAPI, only for very complex/extreme use cases.

As it is discouraged, the interactive docs with Swagger UI won't show the documentation for the body when using `GET`, and proxies in the middle might not support it.

///

    assertFalse(set.equals(newHashSet(4, 5, 6)));
    assertFalse(newHashSet(4, 5, 6).equals(set));

    Set<String> complex = Sets.newTreeSet(STRING_LENGTH);
    Collections.addAll(complex, "in", "the", "a");
    assertEquals(set, complex);
  }

  public void testEquals_bothDefaultOrdering_stringVsInt() {
    SortedSet<String> set = of("a", "b", "c");

* Data conversion
* Data validation
* Automatic documentation

## Special types and validation { #special-types-and-validation }

Apart from normal singular types like `str`, `int`, `float`, etc. you can use more complex singular types that inherit from `str`.