// Forwarder forwards all incoming HTTP requests to configured transport.
type Forwarder struct {
	RoundTripper http.RoundTripper
	PassHost     bool
	Logger       func(error)
	ErrorHandler func(http.ResponseWriter, *http.Request, error)

	// internal variables
	rewriter *headerRewriter
}

// NewForwarder creates an instance of Forwarder based on the provided list of configuration options

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester to ensure forwarding wrapper works by delegating calls to the corresponding method with
 * the same parameters forwarded and return value forwarded back or exception propagated as is.
 *
 * <p>For example:
 *
 * <pre>{@code
 * new ForwardingWrapperTester().testForwarding(Foo.class, new Function<Foo, Foo>() {
 *   public Foo apply(Foo foo) {

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester to ensure forwarding wrapper works by delegating calls to the corresponding method with
 * the same parameters forwarded and return value forwarded back or exception propagated as is.
 *
 * <p>For example:
 *
 * <pre>{@code
 * new ForwardingWrapperTester().testForwarding(Foo.class, new Function<Foo, Foo>() {
 *   public Foo apply(Foo foo) {

    forward.invalidateAll();
    verify(mock).invalidateAll();
  }

  public void testSize() {
    when(mock.size()).thenReturn(0L);
    assertEquals(0, forward.size());
  }

  public void testStats() {
    when(mock.stats()).thenReturn(null);
    assertNull(forward.stats());
  }

  public void testAsMap() {
    when(mock.asMap()).thenReturn(null);
    assertNull(forward.asMap());
  }

    forward.invalidateAll();
    verify(mock).invalidateAll();
  }

  public void testSize() {
    when(mock.size()).thenReturn(0L);
    assertEquals(0, forward.size());
  }

  public void testStats() {
    when(mock.stats()).thenReturn(null);
    assertNull(forward.stats());
  }

  public void testAsMap() {
    when(mock.asMap()).thenReturn(null);
    assertNull(forward.asMap());
  }

    assertSame(Boolean.TRUE, forward.apply("key"));
  }

  public void testInvalidate() {
    forward.invalidate("key");
    verify(mock).invalidate("key");
  }

  public void testRefresh() throws ExecutionException {
    forward.refresh("key");
    verify(mock).refresh("key");
  }

  public void testInvalidateAll() {
    forward.invalidateAll();
    verify(mock).invalidateAll();
  }

    assertSame(Boolean.TRUE, forward.apply("key"));
  }

  public void testInvalidate() {
    forward.invalidate("key");
    verify(mock).invalidate("key");
  }

  public void testRefresh() throws ExecutionException {
    forward.refresh("key");
    verify(mock).refresh("key");
  }

  public void testInvalidateAll() {
    forward.invalidateAll();
    verify(mock).invalidateAll();
  }

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A set which forwards all its method calls to another set. Subclasses should override one or more
 * methods to modify the behavior of the backing set as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingSet} forward <b>indiscriminately</b> to the

 * interface-specific subclass of {@code ForwardingObject}, such as {@link ForwardingList}, to
 * preserve equality behavior, or override {@code equals} directly.
 *
 * <p>The {@code toString} method is forwarded to the delegate. Although this class does not
 * implement {@link Serializable}, a serializable subclass may be created since this class has a
 * parameter-less constructor.
 *
 * @author Mike Bostock
 * @since 2.0
 */

/**
 * A sorted map which forwards all its method calls to another sorted map. Subclasses should
 * override one or more methods to modify the behavior of the backing sorted map as desired per the
 * <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingSortedMap} forward <i>indiscriminately</i> to