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,

    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,

    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,

{* ../../docs_src/handling_errors/tutorial002_py39.py hl[14] *}

## Install custom exception handlers { #install-custom-exception-handlers }

You can add custom exception handlers with <a href="https://www.starlette.dev/exceptions/" class="external-link" target="_blank">the same exception utilities from Starlette</a>.

Let's say you have a custom exception `UnicornException` that you (or a library you use) might `raise`.

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

### Exceptions auslösen { #raise-exceptions }

Die Abhängigkeiten können Exceptions `raise`n, genau wie normale Abhängigkeiten:

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

### Rückgabewerte { #return-values }

    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,

```

### Exception Handling
```java
import org.codelibs.core.exception.*;

// Runtime exception wrappers eliminate try-catch boilerplate
try {
    // Code that might throw checked exceptions
    return ClassUtil.newInstance(className); // Wraps checked exceptions automatically
} catch (ClassNotFoundRuntimeException e) {
    // Handle the wrapped exception

 * includes both natural exceptions such as unreachable servers, as well as synthetic exceptions
 * when responses are of an unexpected type or cannot be decoded.
 *
 * Other exception types cancel the current call:
 *
 *  * For synchronous calls made with [Call.execute], the exception is propagated to the caller.
 *