* that traverses the elements in {@code a}, followed by the elements in {@code b}. The source
   * iterators are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input
   * iterator supports it.
   *
   * <p><b>{@code Stream} equivalent:</b> {@link Stream#concat}.
   *
   * @since 20.0
   */
  public static <T extends @Nullable Object> FluentIterable<T> concat(

[Conscrypt][conscrypt], which integrates [BoringSSL](https://github.com/google/boringssl) with Java. OkHttp will use Conscrypt if it is
the first security provider:

```java
Security.insertProviderAt(Conscrypt.newProvider(), 1);
```

The OkHttp `3.12.x` branch supports Android 2.3+ (API level 9+) and Java 7+. These platforms lack
support for TLS 1.2 and should not be used.

   * traverses the elements in {@code a}, followed by the elements in {@code b}. The source
   * iterators are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input
   * iterator supports it.
   *
   * <p><b>Java 8+ users:</b> The {@code Stream} equivalent of this method is {@code
   * Stream.concat(a, b)}.
   */

        fileInputStream.mark(readlimit);
    }

    /**
     * Tests if this input stream supports the mark and reset methods.
     * This method delegates to {@link FileInputStream#markSupported()}.
     *
     * @return {@code true} if this stream type supports the mark and reset method; {@code false} otherwise
     */
    @Override
    public boolean markSupported() {

   * traverses the elements in {@code a}, followed by the elements in {@code b}. The source
   * iterators are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input
   * iterator supports it.
   *
   * <p><b>Java 8+ users:</b> The {@code Stream} equivalent of this method is {@code
   * Stream.concat(a, b)}.
   */

 *
 * <p>Key features:</p>
 * <ul>
 *   <li>Supports multiple user-agent directives with pattern matching</li>
 *   <li>Handles Allow and Disallow rules for path-based access control</li>
 *   <li>Manages crawl delay settings per user agent</li>
 *   <li>Stores sitemap URLs listed in robots.txt</li>
 * </ul>
 *
 * <p>The class uses case-insensitive pattern matching for user agents and supports

   * elements in {@code a}, followed by the elements in {@code b}. The source iterators are not
   * polled until necessary.
   *
   * <p>The returned iterator supports {@code remove()} when the corresponding input iterator
   * supports it.
   */
  public static <T extends @Nullable Object> Iterator<T> concat(
      Iterator<? extends T> a, Iterator<? extends T> b) {
    checkNotNull(a);
    checkNotNull(b);

 * session events and their originating operations in the application code. The trace structure
 * supports the following key features:
 *
 * <ul>
 *   <li>Maintains parent-child relationships between requests to track operation nesting</li>
 *   <li>Carries contextual data describing the current request or operation</li>
 *   <li>Supports both internal session operations and client-provided trace information</li>
 * </ul>
 *

}

// Error implements Error interface
func (b BatchJobYamlErr) Error() string {
	return fmt.Sprintf("%s\n Hint: error near line: %d, col: %d", b.msg, b.line, b.col)
}

// BatchJobKV is a key-value data type which supports wildcard matching
type BatchJobKV struct {
	line, col int
	Key       string `yaml:"key" json:"key"`
	Value     string `yaml:"value" json:"value"`
}

var _ yaml.Unmarshaler = &BatchJobKV{}

So, even with the code above that doesn't use Pydantic explicitly, FastAPI is using Pydantic to convert those standard dataclasses to Pydantic's own flavor of dataclasses.

And of course, it supports the same:

* data validation
* data serialization
* data documentation, etc.