They can declare request requirements (like headers) or other sub-dependencies:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[8,13] *}

### Raise exceptions { #raise-exceptions }

These dependencies can `raise` exceptions, the same as normal dependencies:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[10,15] *}

### Return values { #return-values }

@Experimental
public interface VersionRangeResolverResult extends Result<VersionRangeResolverRequest> {

    /**
     * Gets the exceptions that occurred while resolving the version range.
     *
     * @return The list of exceptions that occurred during resolution, never {@code null}
     */
    @Nonnull
    List<Exception> getExceptions();

    /**
     * Gets the versions (in ascending order) that matched the requested range.
     *

You can override these exception handlers with your own.

### Override request validation exceptions { #override-request-validation-exceptions }

When a request contains invalid data, **FastAPI** internally raises a `RequestValidationError`.

And it also includes a default exception handler for it.

                    conn.connect();
                    successCount.incrementAndGet();
                } catch (Exception e) {
                    synchronized (exceptions) {
                        exceptions.add(e);
                    }
                    failureCount.incrementAndGet();
                } finally {
                    doneLatch.countDown();
                }

    PLATFORM {
      @GwtIncompatible
      @J2ktIncompatible
      @Override
      // returns the types available in "normal" environments
      ImmutableMap<Class<? extends Throwable>, Predicate<Throwable>> exceptions() {
        return ImmutableMap.of(
            InvocationTargetException.class,
            e -> e instanceof InvocationTargetException,
            StackOverflowError.class,

    PLATFORM {
      @GwtIncompatible
      @J2ktIncompatible
      @Override
      // returns the types available in "normal" environments
      ImmutableMap<Class<? extends Throwable>, Predicate<Throwable>> exceptions() {
        return ImmutableMap.of(
            InvocationTargetException.class,
            e -> e instanceof InvocationTargetException,
            StackOverflowError.class,

    ).containsExactly(
      "--> GET http://google.com/robots.txt",
      "<-- HTTP FAILED: java.net.UnknownHostException: shortcircuit. ${request.url} (ms)",
    )
    // We should consider if these logs should retain Exceptions
    assertThat(logs.last().throwable).isNull()
  }

  @Test
  fun testLoggingEventListener() {
    val client = clientBuilder.eventListenerFactory(LoggingEventListener.Factory()).build()

    try {

                    conn.connect();
                    successCount.incrementAndGet();
                } catch (Exception e) {
                    synchronized (exceptions) {
                        exceptions.add(e);
                    }
                    failureCount.incrementAndGet();
                } finally {
                    doneLatch.countDown();
                }

Aber es ist für Sie da, wenn Sie es brauchen. 🤓

///

{* ../../docs_src/dependencies/tutorial008b_an_py39.py hl[18:22,31] *}

    }

    /**
     * Closes the stream and deletes the temporary file if it was not retrieved.
     * If an error occurs during file deletion, it is logged but not thrown to avoid
     * masking exceptions from the main operation.
     *
     * @throws IOException if an I/O error occurs during stream closure
     */
    @Override
    public void close() throws IOException {
        try {
            super.close();