if err != nil {
				t.Fatalf("Test %q: Initializing reader failed %s", testCase.desc, err)
			}
			_, err = io.Copy(io.Discard, r)
			if err != nil {
				if testCase.err == nil {
					t.Errorf("Test %q; got unexpected error: %v", testCase.desc, err)
					return
				}
				if err.Error() != testCase.err.Error() {
					t.Errorf("Test %q: Expected error %s, got error %s", testCase.desc, testCase.err, err)

import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates collections, containing sample elements, to be tested.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestCollectionGenerator<E extends @Nullable Object>

 * object being tested for equality to the custom interface. {@code ForwardingObject} implements no
 * such custom interfaces directly; they are implemented only in subclasses. Therefore, forwarding
 * {@code equals} would break symmetry, as the forwarding object might consider itself equal to the
 * object being tested, but the reverse could not be true. This behavior is consistent with the

    assertFalse(future.isDone());
    assertTrue(future.setException(new Exception("failure")));
    tester.testFailedFuture("failure");
  }

  public void testCancel() throws Exception {
    assertTrue(future.cancel(true));
    tester.testCancelledFuture();
  }

  /** Tests the initial state of the future. */
  public void testCreate() throws Exception {
    SettableFuture<Integer> future = SettableFuture.create();

 */

package com.google.common.collect.testing.features;

import com.google.common.annotations.GwtCompatible;
import java.util.Set;

/**
 * Base class for enumerating the features of an interface to be tested.
 *
 * @param <T> The interface whose features are to be enumerated.
 * @author George van den Driessche
 */
@GwtCompatible
public interface Feature<T> {

import com.google.common.annotations.GwtCompatible;
import java.util.Map;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates maps, containing sample elements, to be tested.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestMapGenerator<K extends @Nullable Object, V extends @Nullable Object>

import com.google.common.annotations.GwtCompatible;
import java.util.List;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates sets, containing sample elements, to be tested.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestListGenerator<E extends @Nullable Object> extends TestCollectionGenerator<E> {
  @Override

/**
 * Testers for {@link SetMultimap#asMap}.
 *
 * @author Louis Wasserman
 * @param <K> The key type of the tested multimap.
 * @param <V> The value type of the tested multimap.
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@ElementTypesAreNonnullByDefault

| Android default  | ✅      | Android 10+  | [BoringSSL]     |                                                              |
| [GraalVM]        | ✅      |              | [OpenJDK]       | Only actively tested with JDK 11, not with 8 target          |
| [Bouncy Castle]  | ✅      |              | [Bouncy Castle] | [Tracking bug.][bug5698]                                     |

If the nested type is a managed type (Gradle can generate its implementation), you can define a nested property with:
```
interface NestedType {
    Property<String> getSomeProperty()
}
class Example {
    @Nested
    NestedType getNestedProperty()
}
```