* used; or if the class exposes a public parameter-less constructor then it will be "new"d and
 * returned.
 *
 * <p>All default instances returned by {@link #get} are generics-safe. Clients won't get type
 * errors for using {@code get(Comparator.class)} as a {@code Comparator<Foo>}, for example.
 * Immutable empty instances are returned for collection types; {@code ""} for string; {@code 0} for

     * the configuration type and delegates to the appropriate service.
     *
     * @param configId the configuration ID to retrieve
     * @return the CrawlingConfig object or null if not found or on error
     */
    public CrawlingConfig getCrawlingConfig(final String configId) {
        try {
            return crawlingConfigCache.get(configId, () -> {

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009c.py!}
```

🔢 `name` 🔬 `Optional[str]`, ✋️ ⚫️ **🚫 📦**, 👆 🚫🔜 🤙 🔢 🍵 🔢:

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

`name` 🔢 **✔** (🚫 *📦*) ↩️ ⚫️ 🚫 ✔️ 🔢 💲. , `name` 🚫 `None` 💲:

```Python
say_hi(name=None)  # This works, None is valid 🎉
```

                            } else if (logger.isWarnEnabled()) {
                                logger.warn(msg);
                            } else if (logger.isErrorEnabled()) {
                                logger.error(msg);
                            }
                        }
                    } catch (final Exception e) {
                        logger.warn(e.getLocalizedMessage());
                    }

////

/// info

In Pydantic version 1 the configuration was done in an internal class `Config`, in Pydantic version 2 it's done in an attribute `model_config`. This attribute takes a `dict`, and to get autocompletion and inline errors you can import and use `SettingsConfigDict` to define that `dict`.

///

Here we define the config `env_file` inside of your Pydantic `Settings` class, and set the value to the filename with the dotenv file we want to use.

  // 'test' to demonstrate some potentially ambiguous overloads.  This 'test' is kind of strange,
  // but essentially each line will be a call to a Preconditions method that, but for a documented
  // change would be a compiler error.
  // See http://docs.oracle.com/javase/specs/jls/se7/html/jls-15.html#jls-15.12.2 for the spec on
  // how javac selects overloads
  @SuppressWarnings("null")
  public void overloadSelection() {

  // 'test' to demonstrate some potentially ambiguous overloads.  This 'test' is kind of strange,
  // but essentially each line will be a call to a Preconditions method that, but for a documented
  // change would be a compiler error.
  // See http://docs.oracle.com/javase/specs/jls/se7/html/jls-15.html#jls-15.12.2 for the spec on
  // how javac selects overloads
  @SuppressWarnings("null")
  public void overloadSelection() {

            // When & Then
            assertThrows(CIFSException.class, () -> transportPool.getChallenge(context, address));
        }
    }

    @Nested
    @DisplayName("Edge Cases and Error Handling")
    class EdgeCasesTests {

        @Test
        @DisplayName("Should handle null context")
        void testNullContext() {
            // Given

    //                                                                        ============
    /**
     * Verifies that the provided CRUD mode matches the expected mode.
     * Throws a validation error if the modes do not match.
     *
     * @param crudMode the actual CRUD mode
     * @param expectedMode the expected CRUD mode
     */
    protected void verifyCrudMode(final int crudMode, final int expectedMode) {

 * <p>Event subscriber methods must accept only one argument: the event.
 *
 * <p>Subscribers should not, in general, throw. If they do, the EventBus will catch and log the
 * exception. This is rarely the right solution for error handling and should not be relied upon; it
 * is intended solely to help find problems during development.
 *
 * <p>The EventBus guarantees that it will not call a subscriber method from multiple threads