## Testing Best Practices

1. **Isolation**: Each test is independent and doesn't affect others
2. **Clarity**: Test names clearly describe what is being tested
3. **Coverage**: Both success and failure paths are tested
4. **Edge Cases**: Null, empty, and boundary conditions are covered
5. **Resources**: Test resources are properly managed and cleaned up

## Contributing

When adding new tests:

                    <version>25</version>
                    <vendor>temurin</vendor>
                  </jdk>
                  <testJdk>
                    <version>${surefire.toolchain.version}</version>
                    <vendor>temurin</vendor>
                  </testJdk>
                </toolchains>
              </configuration>
            </execution>
          </executions>
        </plugin>

                    <version>25</version>
                    <vendor>temurin</vendor>
                  </jdk>
                  <testJdk>
                    <version>${surefire.toolchain.version}</version>
                    <vendor>temurin</vendor>
                  </testJdk>
                </toolchains>
              </configuration>
            </execution>
          </executions>
        </plugin>

  static final String ERROR_ADDED_SELF_LOOP = "Should not be allowed to add a self-loop edge.";

  /** Creates and returns an instance of the graph to be tested. */
  abstract Graph<Integer> createGraph();

  /**
   * A proxy method that adds the node {@code n} to the graph being tested. In case of Immutable
   * graph implementations, this method should replace {@link #graph} with a new graph that includes
   * this node.
   */

  static final String ERROR_ADDED_SELF_LOOP = "Should not be allowed to add a self-loop edge.";

  /** Creates and returns an instance of the graph to be tested. */
  abstract Graph<Integer> createGraph();

  /**
   * A proxy method that adds the node {@code n} to the graph being tested. In case of Immutable
   * graph implementations, this method should replace {@link #graph} with a new graph that includes
   * this node.
   */

import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link Files}.
 *
 * <p>Some methods are tested in separate files:
 *
 * <ul>
 *   <li>{@link Files#fileTraverser()} is tested in {@link FilesFileTraverserTest}.
 *   <li>{@link Files#createTempDir()} is tested in {@link FilesCreateTempDirTest}.
 * </ul>
 *
 * @author Chris Nokleberg
 */

import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link Files}.
 *
 * <p>Some methods are tested in separate files:
 *
 * <ul>
 *   <li>{@link Files#fileTraverser()} is tested in {@link FilesFileTraverserTest}.
 *   <li>{@link Files#createTempDir()} is tested in {@link FilesCreateTempDirTest}.
 * </ul>
 *
 * @author Chris Nokleberg
 */

    for (long a : TEST_LONGS) {
      assertThrows(
          ArithmeticException.class,
          () -> UnsignedLong.fromLongBits(a).dividedBy(UnsignedLong.ZERO));
    }
  }

  public void testMod() {
    for (long a : TEST_LONGS) {
      for (long b : TEST_LONGS) {
        if (b != 0) {
          UnsignedLong aUnsigned = UnsignedLong.fromLongBits(a);

    /*
     * We'll give ourselves a pass on testing all the possible ways of breaking the constraint,
     * because we know that newClassMap() is implemented using ConstrainedMap which is itself
     * well-tested. A purist would object to this, but what can I say, we're dirty cheaters.
     */
    map.put(Integer.class, new Integer(5));
    assertThrows(ClassCastException.class, () -> map.put(Double.class, new Long(42)));

import okhttp3.internal.http.RealInterceptorChain
import okhttp3.internal.http.RecordingProxySelector
import okhttp3.tls.HandshakeCertificates
import okhttp3.tls.internal.TlsUtil.localhost

/**
 * OkHttp is usually tested with functional tests: these use public APIs to confirm behavior against
 * MockWebServer. In cases where logic is particularly tricky, we use unit tests. This class makes
 * it easy to get sample values to use in such tests.
 *