* @param <V4> the type returned by the fourth future
   */
  public static final class Combiner4<
          V1 extends @Nullable Object,
          V2 extends @Nullable Object,
          V3 extends @Nullable Object,
          V4 extends @Nullable Object>
      extends Combiner {
    /**
     * A function that returns a value when applied to the values of the four futures passed to

  private abstract static class Third<T, D> extends Second<T> {}

  private abstract static class Fourth<T, D> extends Third<D, T> {}

  private static class ConcreteIntegerString extends Fourth<Integer, String> {}

  private static class ConcreteStringInteger extends Fourth<String, Integer> {}

  public void testAssignableClassToClass() {
    @SuppressWarnings("rawtypes") // To test TypeToken<List>

    }

    /**
     * Test multiple name changes
     */
    public void test_multipleNameChanges() {
        String[] names = { "first", "second", "third", "fourth", "fifth" };

        for (String name : names) {
            testTransformer.setName(name);
            assertEquals(name, testTransformer.getName());
        }

        // Verify final state

  }

  private static final class PaddedLock extends ReentrantLock {
    /*
     * Padding from 40 into 64 bytes, same size as cache line. Might be beneficial to add a fourth
     * long here, to minimize chance of interference between consecutive locks, but I couldn't
     * observe any benefit from that.
     */
    long unused1;
    long unused2;
    long unused3;

        .url(url)
        .query("bar".toRequestBody())
        .build()
    val response3 = client.newCall(request3).execute()
    assertThat(response3.body.string()).isEqualTo("DEFa")

    // Fourth QUERY request with body "foo" again, should be cached and return "ABC"
    val response1a = client.newCall(request1).execute()
    assertThat(response1a.body.string()).isEqualTo("ABC")

3389225,2,2014-03-31 09:42:15,2014-03-31 10:01:17,N,1,-73.950340270996094,40.792228698730469,-73.941970825195313,40.842235565185547,1,4.47,17.5,0,0.5,0,0,,,18,2,1,75,244,green,0.16,0.0,0.0,56,36,8.28,1267,168,1,Manhattan,016800,1016800,E,MN33,East Harlem South,3804,911,251,1,Manhattan,025100,1025100,E,MN36,Washington Heights South,3801

Australia/Brisbane Australia/Broken_Hill Australia/Canberra Australia/Currie Australia/Darwin Australia/Eucla Australia/Hobart Australia/LHI Australia/Lindeman Australia/Lord_Howe Australia/Melbourne Australia/NSW Australia/North Australia/Perth Australia/Queensland Australia/South Australia/Sydney Australia/Tasmania Australia/Victoria Australia/West Australia/Yancowinna Brazil/Acre Brazil/DeNoronha Brazil/East Brazil/West CET CST6CDT Canada/Atlantic Canada/Central Canada/Eastern Canada/Mountain Canada/Newfoundland...

            .put("three", 3)
            .put("one", 1)
            .put("five", 5)
            .put("four", 3)
            .put("four", 5)
            .put("four", 4) // this should win because it's last
            .put("two", 2);
    assertMapEquals(
        builder.buildKeepingLast(), "one", 1, "two", 2, "three", 3, "four", 4, "five", 5);
    assertThrows(IllegalArgumentException.class, () -> builder.buildOrThrow());
  }

* key (as in key-value pair, dictionary key): clave
* array (as in JSON array): array
* API key: API key (do not translate to "clave API")
* 100% test coverage: cobertura de tests del 100%
* back and forth: de un lado a otro
* I/O (as in "input and output"): I/O (do not translate to "E/S")
* Machine Learning: Machine Learning (do not translate to "Aprendizaje Automático")

For gradual adoption, enable checks project-by-project.
Do not rely on `@NullMarked` annotations.
Only enable checks for a project if all its dependencies have checks enabled, in order to avoid back-and-forth when refining the annotations.

Avoid writing the so-called `PolyNull` or `ParametricNull` methods (where nullability of the result depends on the nullability of the type argument).