public static <T extends @Nullable Object> Iterable<T> concat(
      Iterable<? extends T> a, Iterable<? extends T> b, Iterable<? extends T> c) {
    return FluentIterable.concat(a, b, c);
  }

  /**
   * Combines four iterables into a single iterable. The returned iterable has an iterator that
   * traverses the elements in {@code a}, followed by the elements in {@code b}, followed by the

  public static <T extends @Nullable Object> Iterable<T> concat(
      Iterable<? extends T> a, Iterable<? extends T> b, Iterable<? extends T> c) {
    return FluentIterable.concat(a, b, c);
  }

  /**
   * Combines four iterables into a single iterable. The returned iterable has an iterator that
   * traverses the elements in {@code a}, followed by the elements in {@code b}, followed by the

      assertIntact(queue);
      assertThat(queue).containsExactlyElementsIn(elements);
    }
  }

  private enum Element {
    ONE,
    TWO,
    THREE,
    FOUR,
    FIVE;
  }

  public void testRandomAddsAndRemoves_duplicateElements() {
    Random random = new Random(0);
    Multiset<Element> elements = HashMultiset.create();

    return ImmutableList.copyOf(SORTED_NUMBER_NAMES.subList(i, j));
  }

  private static final ImmutableList<String> NUMBER_NAMES =
      ImmutableList.of("one", "two", "three", "four", "five", "six", "seven");

  private static final ImmutableList<String> SORTED_NUMBER_NAMES =
      Ordering.<String>natural().immutableSortedCopy(NUMBER_NAMES);

    checkNotNull(a);
    checkNotNull(b);
    checkNotNull(c);
    return concat(consumingForArray(a, b, c));
  }

  /**
   * Combines four iterators into a single iterator. The returned iterator iterates across the
   * elements in {@code a}, followed by the elements in {@code b}, followed by the elements in

    // em space
    assertThat(parse("http://h/\u2003").encodedPath).isEqualTo("/%E2%80%83")
    // three-per-em space
    assertThat(parse("http://h/\u2004").encodedPath).isEqualTo("/%E2%80%84")
    // four-per-em space
    assertThat(parse("http://h/\u2005").encodedPath).isEqualTo("/%E2%80%85")
    // six-per-em space
    assertThat(parse("http://h/\u2006").encodedPath).isEqualTo("/%E2%80%86")
    // figure space

    abstract Equivalence<Object> defaultEquivalence();
  }

  /**
   * A helper object for operating on {@link InternalEntry} instances in a type-safe and efficient
   * manner.
   *
   * <p>For each of the four combinations of strong/weak key and strong/weak value, there are
   * corresponding {@link InternalEntry}, {@link Segment}, and {@link InternalEntryHelper}
   * implementations.
   *

- The `SidecarContainers` feature has graduated to `beta` and is enabled by default. ([#121579](https://github.com/kubernetes/kubernetes/pull/121579), [@gjkim42](https://github.com/gjkim42))
- The `kube-apiserver` will now expose four new metrics to inform about errors on the clusterIP and nodePort allocation logic. ([#120843](https://github.com/kubernetes/kubernetes/pull/120843), [@aojea](https://github.com/aojea))

* Performance test framework and basic tests for the IPAM controller, to simulate behavior of the four supported modes under lightly loaded and loaded conditions, where load is defined as the number of operations to perform as against the configured kubernetes. ([#61143](https://github.com/kubernetes/kubernetes/pull/61143), [@satyasm](https://github.com/satyasm))...

used space on volumes created using vSphere. ([#59328](https://github.com/kubernetes/kubernetes/pull/59328), [@divyenpatel](https://github.com/divyenpatel))

* Emit number of bound and unbound persistent volumes as Metrics. This PR adds four kinds of Volume Metrics for kube-controller-manager: bound PVC numbers, unbound PVC numbers, bound PV numbers and unbound PV numbers. The PVC metrics use namespace as dimension and the PV metrics use StorageClassName as its dimension. With these metrics...