[Mockito](https://github.com/mockito/mockito):

1. Script the mocks.
2. Run application code.
3. Verify that the expected requests were made.

Here's a complete example:

```java
public void test() throws Exception {
  // Create a MockWebServer. These are lean enough that you can create a new
  // instance for every unit test.
  MockWebServer server = new MockWebServer();

  // Schedule some responses.

   *
   * <p>If the dataset contains any non-finite values ({@link Double#POSITIVE_INFINITY}, {@link
   * Double#NEGATIVE_INFINITY}, or {@link Double#NaN}) then the result is {@link Double#NaN}.
   *
   * @throws IllegalStateException if the dataset is empty
   */
  public double populationCovariance() {
    checkState(count() != 0);
    return sumOfProductsOfDeltas / count();
  }

  /**

        return new DefaultMavenParser();
    }

    @Test
    void defaultFs(@TempDir(cleanup = CleanupMode.ON_SUCCESS) Path tempDir) throws Exception {
        invoke(tempDir, Arrays.asList("clean", "verify"));
    }

    @Disabled("Until we move off fully from File")
    @Test
    void jimFs() throws Exception {
        try (FileSystem fs = Jimfs.newFileSystem(Configuration.unix())) {

    private static final Logger logger = LogManager.getLogger(GsaConfigParserTest.class);

    @Override
    public void setUp() throws Exception {
        super.setUp();
        ComponentUtil.register(new SystemHelper(), "systemHelper");
    }

    public void test_parse() throws IOException {
        GsaConfigParser parser = new GsaConfigParser();

  @AndroidIncompatible // no FpUtils and no Math.nextDown in old versions
  public void testNextDown() throws Exception {
    Method jdkNextDown = getJdkNextDown();
    for (double d : FINITE_DOUBLE_CANDIDATES) {
      assertEquals(jdkNextDown.invoke(null, d), DoubleUtils.nextDown(d));
    }
  }

  private static Method getJdkNextDown() throws Exception {
    try {
      return Math.class.getMethod("nextDown", double.class);

   *
   * <p>Calls to {@code peek()} should not change the state of the iteration, except that it
   * <i>may</i> prevent removal of the most recent element via {@link #remove()}.
   *
   * @throws NoSuchElementException if the iteration has no more elements according to {@link
   *     #hasNext()}
   */
  @ParametricNullness
  E peek();

  /**
   * {@inheritDoc}
   *

  /**
   * Returns the result of dividing this by {@code val}.
   *
   * @throws ArithmeticException if {@code val} is zero
   * @since 14.0
   */
  public UnsignedInteger dividedBy(UnsignedInteger val) {
    return fromIntBits(UnsignedInts.divide(value, checkNotNull(val).value));
  }

  /**
   * Returns this mod {@code val}.
   *
   * @throws ArithmeticException if {@code val} is zero
   * @since 14.0
   */

  /**
   * Returns the result of dividing this by {@code val}.
   *
   * @throws ArithmeticException if {@code val} is zero
   * @since 14.0
   */
  public UnsignedInteger dividedBy(UnsignedInteger val) {
    return fromIntBits(UnsignedInts.divide(value, checkNotNull(val).value));
  }

  /**
   * Returns this mod {@code val}.
   *
   * @throws ArithmeticException if {@code val} is zero
   * @since 14.0
   */

        runner.ensureYellow();
    }

    @AfterClass
    public static void afterClass() throws Exception {
        runner.close();
        runner.clean();
    }

    @Before
    public void before() throws Exception {
        try {
            runner.admin().indices().prepareDelete("_all").execute().actionGet();
        } catch (IndexNotFoundException ignore) {

    public int value;

    public NdrSmall(int value) {
        this.value = value & 0xFF;
    }

    public void encode(NdrBuffer dst) throws NdrException {
        dst.enc_ndr_small(value);
    }
    public void decode(NdrBuffer src) throws NdrException {
        value = src.dec_ndr_small();
    }