* {@linkplain Thread#getContextClassLoader() context class loader}. In simple environments, the
   * context class loader will find resources from the class path. In environments where different
   * threads can have different class loaders, for example app servers, the context class loader
   * will typically have been set to an appropriate loader for the current thread.
   *

      assertThrows(NullPointerException.class, () -> keys.toArray((Object[]) null));
      checkEmpty(cache);
    }
  }

  public void testKeySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {
      assertThrows(UnsupportedOperationException.class, () -> cache.asMap().keySet().add(1));

      assertThrows(

      assertThrows(NullPointerException.class, () -> keys.toArray((Object[]) null));
      checkEmpty(cache);
    }
  }

  public void testKeySet_addNotSupported() {
    for (LoadingCache<Object, Object> cache : caches()) {
      assertThrows(UnsupportedOperationException.class, () -> cache.asMap().keySet().add(1));

      assertThrows(

    checkResult(J, ITERABLE_123, "1-2-3");

    assertThrows(NullPointerException.class, () -> J.join(ITERABLE_NULL));
    assertThrows(NullPointerException.class, () -> J.join(ITERABLE_1_NULL_2));

    assertThrows(NullPointerException.class, () -> J.join(ITERABLE_NULL.iterator()));
    assertThrows(NullPointerException.class, () -> J.join(ITERABLE_1_NULL_2.iterator()));
  }

  public void testOnCharOverride() {

    Iterable<String> iterable = asList("foo", "bar");
    assertThrows(IllegalArgumentException.class, () -> getOnlyElement(iterable, "x"));
  }

  @GwtIncompatible // Iterables.toArray(Iterable, Class)
  public void testToArrayEmpty() {
    Iterable<String> iterable = emptyList();
    String[] array = Iterables.toArray(iterable, String.class);
    assertTrue(Arrays.equals(new String[0], array));
  }

    assertThrows(IllegalArgumentException.class, () -> limiter.tryAcquire(0));
    assertThrows(IllegalArgumentException.class, () -> limiter.tryAcquire(-1));
    assertThrows(IllegalArgumentException.class, () -> limiter.tryAcquire(0, 1, SECONDS));
    assertThrows(IllegalArgumentException.class, () -> limiter.tryAcquire(-1, 1, SECONDS));
  }

  public void testSimpleWithWait() {

      return ImmutableMap.copyOf(introspector.mappings);
    }

    @Override
    void visitClass(Class<?> clazz) {
      visit(clazz.getGenericSuperclass());
      visit(clazz.getGenericInterfaces());
    }

    @Override
    void visitParameterizedType(ParameterizedType parameterizedType) {
      Class<?> rawClass = (Class<?>) parameterizedType.getRawType();
      TypeVariable<?>[] vars = rawClass.getTypeParameters();

    assertThrows(IllegalArgumentException.class, () -> limiter.tryAcquire(0));
    assertThrows(IllegalArgumentException.class, () -> limiter.tryAcquire(-1));
    assertThrows(IllegalArgumentException.class, () -> limiter.tryAcquire(0, 1, SECONDS));
    assertThrows(IllegalArgumentException.class, () -> limiter.tryAcquire(-1, 1, SECONDS));
  }

  public void testSimpleWithWait() {

### Create an `Enum` class

Import `Enum` and create a sub-class that inherits from `str` and from `Enum`.

By inheriting from `str` the API docs will be able to know that the values must be of type `string` and will be able to render correctly.

Then create class attributes with fixed values, which will be the available valid values:

```Python hl_lines="1  6-9"

    setDistinctValues(AbstractGraphBuilder.class, GRAPH_BUILDER_A, GRAPH_BUILDER_B);
    setDistinctValues(Graph.class, IMMUTABLE_GRAPH_A, IMMUTABLE_GRAPH_B);
    setDistinctValues(MutableNetwork.class, mutableNetworkA, mutableNetworkB);
    setDistinctValues(NetworkBuilder.class, NETWORK_BUILDER_A, NETWORK_BUILDER_B);
    setDistinctValues(Network.class, IMMUTABLE_NETWORK_A, IMMUTABLE_NETWORK_B);