* 数据转换
* 数据校验
* 自动生成文档

## 特殊的类型和校验

除了普通的单一值类型（如 `str`、`int`、`float` 等）外，你还可以使用从 `str` 继承的更复杂的单一值类型。

要了解所有的可用选项，请查看关于 <a href="https://docs.pydantic.dev/latest/concepts/types/" class="external-link" target="_blank">来自 Pydantic 的外部类型</a> 的文档。你将在下一章节中看到一些示例。

例如，在 `Image` 模型中我们有一个 `url` 字段，我们可以把它声明为 Pydantic 的 `HttpUrl`，而不是 `str`：

{* ../../docs_src/body_nested_models/tutorial005_py310.py hl[2,8] *}

import org.lastaflute.di.core.SingletonLaContainer;
import org.opensearch.core.xcontent.ToXContent;
import org.opensearch.core.xcontent.XContentBuilder;

/**
 * OpenSearchAccessResult is an implementation of {@link AccessResult} for OpenSearch.
 *
 * @author shinsuke
 *
 */
public class OpenSearchAccessResult extends AccessResultImpl<String> implements ToXContent {

    /**

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;
import org.junit.Ignore;

/**
 * Tests for {@link Multimap#asMap}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 * Tests {@link PluginDescriptorBuilder}.
 *
 */
class PluginDescriptorBuilderTest {

    private PluginDescriptor build(String resource) throws IOException, PlexusConfigurationException {

import com.google.common.testing.SerializableTester;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@link Equivalence}.
 *
 * @author Jige Yu
 */
@NullMarked
@GwtCompatible
public class EquivalenceTest extends TestCase {
  public void testPairwiseEquivalent() {

import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@link FakeTicker}.
 *
 * @author Jige Yu
 */
@GwtCompatible
// We also want to test the TimeUnit overload (especially under GWT, where it's the only option).
@SuppressWarnings("SetAutoIncrementStep_Nanos")
@NullUnmarked

import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicInteger;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Basher test for {@link ConcurrentHashMultiset}: start a bunch of threads, have each of them do
 * operations at random. Each thread keeps track of the per-key deltas that it's directly

import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code iterator} operations on a collection. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Chris Povirk
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

import org.junit.jupiter.params.provider.MethodSource;
import org.junit.jupiter.params.provider.ValueSource;
import org.mockito.junit.jupiter.MockitoExtension;

import jcifs.smb1.netbios.NbtAddress;

/**
 * Unit tests for {@link UniAddress}.  The focus of these tests is on
 * the public API of {@code UniAddress} and its behaviour when provided
 * with different kinds of inputs.  Many static helpers in {@code

import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * A ScheduledExecutorService that executes all scheduled actions immediately in the calling thread.
 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible