if (pcd == null) {
            return null;
        }
        return pcd.getRawClass();
    }

    @Override
    public <T> T invoke(final Object target, final Object... args) {
        assertArgumentNotNull("target", target);

        return MethodUtil.invoke(method, target, args);
    }

    @Override
    public <T> T invokeStatic(final Object... args) {
        if (!isStatic()) {

 * </ul>
 *
 * <p>The main components are:</p>
 * <ul>
 *   <li>{@link org.apache.maven.api.cli.Invoker} - Base interface for executing Maven tools</li>
 *   <li>{@link org.apache.maven.api.cli.Parser} - Processes command-line arguments into invoker requests</li>
 *   <li>{@link org.apache.maven.api.cli.Options} - Represents Maven configuration options</li>

                return 0;
              case 1:
                return 1;
              case 2:
                return endOfData();
              default:
                throw new AssertionError("Should not have been invoked again");
            }
          }
        };

    assertTrue(iter.hasNext());
    assertEquals(0, (int) iter.next());

    // verify idempotence of hasNext()
    assertTrue(iter.hasNext());

    if command -v systemctl >/dev/null; then
        systemctl --no-reload stop fess.service > /dev/null 2>&1 || true

    elif [ -x /etc/init.d/fess ]; then
        if command -v invoke-rc.d >/dev/null; then
            invoke-rc.d fess stop || true
        else
            /etc/init.d/fess stop || true
        fi

    # older suse linux distributions do not ship with systemd
    # but do not have an /etc/init.d/ directory

        String result = (String) method.invoke(keyMatchHelper, "JAVA");
        assertEquals("java", result);

        result = (String) method.invoke(keyMatchHelper, "Mixed_Case");
        assertEquals("mixed_case", result);

        result = (String) method.invoke(keyMatchHelper, (String) null);
        assertNull(result);

        result = (String) method.invoke(keyMatchHelper, "");
        assertEquals("", result);

@J2ktIncompatible
@GwtIncompatible
public interface FinalizableReference {
  /**
   * Invoked on a background thread after the referent has been garbage collected unless security
   * restrictions prevented starting a background thread, in which case this method is invoked when
   * new references are created.
   */
  void finalizeReferent();

  protected AbstractExecutionThreadService() {}

  /**
   * Start the service. This method is invoked on the execution thread.
   *
   * <p>By default this method does nothing.
   */
  protected void startUp() throws Exception {}

  /**
   * Run the service. This method is invoked on the execution thread. Implementations must respond
   * to stop requests. You could poll for lifecycle changes in a work loop:

        assertArgumentNotNull("target", target);

        try {
            assertState(readable, propertyName + " is not readable.");
            if (hasReadMethod()) {
                return MethodUtil.invoke(readMethod, target, EMPTY_ARGS);
            }
            return FieldUtil.get(field, target);
        } catch (final Throwable t) {

## An app with callbacks { #an-app-with-callbacks }

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

These invoices will have an `id`, `title` (optional), `customer`, and `total`.

The user of your API (an external developer) will create an invoice in your API with a POST request.

Then your API will (let's imagine):

 *
 * <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 ForwardingListeningExecutorService}.
 *
 * @author Isaac Shum
 * @since 10.0
 */
@J2ktIncompatible
@GwtIncompatible