static IncrementingLoader incrementingLoader() {
    return new IncrementingLoader();
  }

  /** Returns a {@link CacheLoader} that throws the given error for every request. */
  static <K, V> CacheLoader<K, V> errorLoader(final Error e) {
    checkNotNull(e);
    return new CacheLoader<K, V>() {
      @Override
      public V load(K key) {
        throw e;
      }
    };
  }

   * independent stream each time it is called.
   *
   * <p>The caller is responsible for ensuring that the returned stream is closed.
   *
   * @throws IOException if an I/O error occurs while opening the stream
   */
  public abstract OutputStream openStream() throws IOException;

  /**
   * Opens a new buffered {@link OutputStream} for writing to this sink. The returned stream is not

 *   <li>comparing each pair of objects from different equality groups returns false
 *   <li>the hash codes of any two equal objects are equal
 * </ul>
 *
 * <p>When a test fails, the error message labels the objects involved in the failed comparison as
 * follows:
 *
 * <ul>
 *   <li>"{@code [group }<i>i</i>{@code , item }<i>j</i>{@code ]}" refers to the

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.graph;

import static com.google.common.graph.TestUtil.ERROR_ELEMENT_NOT_IN_GRAPH;
import static com.google.common.truth.Truth.assertWithMessage;

import com.google.common.testing.AbstractPackageSanityTests;
import junit.framework.AssertionFailedError;

/**

/** Utility methods used in various common.graph tests. */
final class TestUtil {
  static final String ERROR_ELEMENT_NOT_IN_GRAPH = "not an element of this graph";
  static final String ERROR_NODE_NOT_IN_GRAPH =
      "Should not be allowed to pass a node that is not an element of the graph.";
  static final String ERROR_ELEMENT_REMOVED = "used to generate this set";
  private static final String NODE_STRING = "Node";

/** Utility methods used in various common.graph tests. */
final class TestUtil {
  static final String ERROR_ELEMENT_NOT_IN_GRAPH = "not an element of this graph";
  static final String ERROR_NODE_NOT_IN_GRAPH =
      "Should not be allowed to pass a node that is not an element of the graph.";
  static final String ERROR_ELEMENT_REMOVED = "used to generate this set";
  private static final String NODE_STRING = "Node";

   * @return this for the builder pattern
   */
  @CanIgnoreReturnValue
  public ThreadFactoryBuilder setPriority(int priority) {
    // Thread#setPriority() already checks for validity. These error messages
    // are nicer though and will fail-fast.
    checkArgument(
        priority >= Thread.MIN_PRIORITY,
        "Thread priority (%s) must be >= %s",
        priority,
        Thread.MIN_PRIORITY);

      immediateFailedFuture(OTHER_THROWABLE);
  static final Error ERROR = new Error("mymessage");
  static final Future<String> FAILED_FUTURE_ERROR = immediateFailedFuture(ERROR);
  static final Future<String> RUNTIME_EXCEPTION_FUTURE =
      UncheckedThrowingFuture.throwingRuntimeException(RUNTIME_EXCEPTION);
  static final Future<String> ERROR_FUTURE = UncheckedThrowingFuture.throwingError(ERROR);

   * except using little-endian byte order.
   *
   * @return the next two bytes of the input stream, interpreted as an unsigned 16-bit integer in
   *     little-endian byte order
   * @throws IOException if an I/O error occurs
   */
  @CanIgnoreReturnValue // to skip some bytes
  @Override
  public int readUnsignedShort() throws IOException {
    byte b1 = readAndCheckByte();
    byte b2 = readAndCheckByte();

    for (int i = 0; i < reps; ++i) {
      if (javaImpl.compare(ba1, ba2) != 0) {
        throw new Error(); // deoptimization
      }
    }
  }

  @Benchmark
  void longEqualUnsafe(int reps) {
    for (int i = 0; i < reps; ++i) {
      if (unsafeImpl.compare(ba1, ba2) != 0) {
        throw new Error(); // deoptimization
      }
    }
  }

  @Benchmark
  void diffLastJava(int reps) {