* filter out incompatible values from its result.
     *
     * @param value The configuration value to preprocess, must not be {@code null}.
     * @param type The target type of the value, may be {@code null}.
     * @return The processed configuration value or {@code null} if none.
     * @throws BeanConfigurationException If an error occurred while preprocessing the value.
     */

These are the exceptions that you can raise to show errors to the client.

When you raise an exception, as would happen with normal Python, the rest of the execution is aborted. This way you can raise these exceptions from anywhere in the code to abort a request and show the error to the client.

You can use:

* `HTTPException`
* `WebSocketException`

These exceptions can be imported directly from `fastapi`:

```python

/**
 * Unmarshals some textual configuration from the POM or similar into the properties of a bean. This component works
 * similar to the way Maven configures plugins from the POM, i.e. some configuration like {@code <param>value</param>}
 * is mapped to an equally named property of the bean and converted. The properties of the bean are supposed to either
 * have a public setter or be backed by an equally named field (of any visibility).
 *

            currentProcess.waitFor();
            it.join(5000);

            final int exitValue = currentProcess.exitValue();

            if (logger.isInfoEnabled()) {
                logger.info("Python: Exit Code={} - Process Output:\n{}", exitValue, it.getOutput());
            }
            if (exitValue != 0) {
                final StringBuilder out = new StringBuilder();
                if (processTimeout) {

    server.enqueue(MockResponse(body = "abc2"))

    val request = Request(server.url("/"))

    client.newCall(request).execute().use { response ->
      assertEquals(200, response.code)
    }

    client.connectionPool.evictAll()
    assertEquals(0, client.connectionPool.connectionCount())

    // Force reuse. This appears flaky (30% of the time) even though sessions are reused.

   * document's character encoding can encode any non-ASCII code points in the input (as UTF-8 and
   * other Unicode encodings can).
   *
   * <p><b>Note:</b> This escaper only performs minimal escaping to make content structurally
   * compatible with HTML. Specifically, it does not perform entity replacement (symbolic or
   * numeric), so it does not replace non-ASCII code points with character references. This escaper

    this.wordBoundary = wordBoundary;
    this.wordSeparator = wordSeparator;
  }

  /**
   * Converts the specified {@code String str} from this format to the specified {@code format}. A
   * "best effort" approach is taken; if {@code str} does not conform to the assumed format, then
   * the behavior of this method is undefined but we make a reasonable effort at converting anyway.
   */

<font color="#3465A4">INFO    </font> Resolved absolute path <font color="#75507B">/home/user/code/awesomeapp/</font><font color="#AD7FA8">main.py</font>
<font color="#3465A4">INFO    </font> Searching for package file structure from directories with <font color="#3465A4">__init__.py</font> files
<font color="#3465A4">INFO    </font> Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingListMultimap}.
 *
 * @author Kurt Alfred Kluever
 * @since 3.0
 */
@GwtCompatible

 * desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingSortedSetMultimap}.
 *
 * @author Kurt Alfred Kluever
 * @since 3.0
 */
@GwtCompatible