import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.ArrayList;
import java.util.List;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tester for equals() and hashCode() methods of a class.
 *
 * <p>The simplest use case is:
 *
 * <pre>
 * new EqualsTester().addEqualityGroup(foo).testEquals();
 * </pre>
 *

   - If you edit, you’re a collaborator, not a reviewer, and cannot merge.

6. **Testing**:
   - Assume the submitter tested the code. If testing is unclear, ask for details (e.g., “How was this tested?”).
   - Reject untested PRs unless testing is infeasible, then assist with test setup.

## Tips for Success

        String field = "content";

        List<String> readings = converter.convert(text, field, "en", "ja", "fr");

        assertNotNull(readings);
        assertEquals(3, readings.size());
        assertEquals("TEST_en", readings.get(0));
        assertEquals("TEST_ja", readings.get(1));
        assertEquals("TEST_fr", readings.get(2));
    }

    @Test
    public void testConvertWithNoLanguages() throws IOException {

 * 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

  public void testNullPointers() {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(Joiner.class);
    tester.testInstanceMethods(Joiner.on(","), NullPointerTester.Visibility.PACKAGE);
    tester.testInstanceMethods(Joiner.on(",").skipNulls(), NullPointerTester.Visibility.PACKAGE);
    tester.testInstanceMethods(

 * limitations under the License.
 */

package com.google.common.collect.testing;

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

/**
 * Creates iterators to be tested.
 *
 * @param <E> the element type of the iterator.
 * @author George van den Driessche
 */
@GwtCompatible
public interface TestIteratorGenerator<E> {
  Iterator<E> get();

import com.google.common.annotations.GwtCompatible;
import java.util.Queue;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates queues, containing sample elements, to be tested.
 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public interface TestQueueGenerator<E extends @Nullable Object> extends TestCollectionGenerator<E> {
  @Override
  Queue<E> create(Object... elements);

import com.google.common.annotations.GwtCompatible;
import java.util.List;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

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

import com.google.common.annotations.GwtCompatible;
import java.util.Map;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

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

import com.google.common.collect.testing.TestCollectionGenerator;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates multisets, containing sample elements, to be tested.
 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public interface TestMultisetGenerator<E extends @Nullable Object>
    extends TestCollectionGenerator<E> {
  @Override