ImmutableSortedSet<E> result = (ImmutableSortedSet<E>) elements;
      boolean isSubset =
          (result instanceof RegularImmutableSortedSet)
              && ((RegularImmutableSortedSet) result).isSubset;
      if (!isSubset) {
        // Only return the original copy if this immutable sorted set isn't
        // a subset of another, to avoid memory leak.
        return result;
      }
    }

      for (int j = i + 1; j <= 20; j++) {
        assertEquals(expectedSet.subSet(i, false, j, false), asSet.subSet(i, false, j, false));
        assertEquals(expectedSet.subSet(i, true, j, false), asSet.subSet(i, true, j, false));
        assertEquals(expectedSet.subSet(i, false, j, true), asSet.subSet(i, false, j, true));
        assertEquals(expectedSet.subSet(i, true, j, true), asSet.subSet(i, true, j, true));
      }
    }
  }

metadata:
  name: valid-virtual-service
spec:
  hosts:
    - c
  http:
    - route:
      - destination:
          host: c
          subset: v1
        weight: 75
      - destination:
          host: c
          subset: v2
        weight: 25`
	validVirtualServiceJSON = `{
"apiVersion": "networking.istio.io/v1alpha3",
"kind": "VirtualService",
"metadata": {

    SortedSet<String> subset = elementSet.subSet("b", "f");
    assertThat(subset).containsExactly("b", "c", "d", "e").inOrder();

    assertTrue(subset.remove("c"));
    assertThat(elementSet).containsExactly("a", "b", "d", "e", "f").inOrder();
    assertThat(subset).containsExactly("b", "d", "e").inOrder();
    assertEquals(10, ms.size());

    assertFalse(subset.remove("a"));

    SortedSet<String> subset = elementSet.subSet("b", "f");
    assertThat(subset).containsExactly("b", "c", "d", "e").inOrder();

    assertTrue(subset.remove("c"));
    assertThat(elementSet).containsExactly("a", "b", "d", "e", "f").inOrder();
    assertThat(subset).containsExactly("b", "d", "e").inOrder();
    assertEquals(10, ms.size());

    assertFalse(subset.remove("a"));

    assertEquals(ImmutableSortedSet.of(4, 6, 8, 10), Sets.subSet(set, Range.atLeast(4)));
    assertEquals(ImmutableSortedSet.of(8, 10), Sets.subSet(set, Range.atLeast(7)));
    assertEquals(empty, Sets.subSet(set, Range.atLeast(20)));

    assertEquals(set, Sets.subSet(set, Range.greaterThan(0)));
    assertEquals(ImmutableSortedSet.of(6, 8, 10), Sets.subSet(set, Range.greaterThan(4)));

    assertThat(set.subSet(1, 4)).containsExactly(1, 2, 3).inOrder();
    assertThat(set.subSet(2, 4)).containsExactly(2, 3).inOrder();
    assertThat(set.subSet(3, 4)).containsExactly(3).inOrder();
    assertThat(set.subSet(3, 3)).isEmpty();
    assertThat(set.subSet(2, 3)).containsExactly(2).inOrder();
    assertThat(set.subSet(1, 3)).containsExactly(1, 2).inOrder();

    assertThat(set.subSet(1, 4)).containsExactly(1, 2, 3).inOrder();
    assertThat(set.subSet(2, 4)).containsExactly(2, 3).inOrder();
    assertThat(set.subSet(3, 4)).containsExactly(3).inOrder();
    assertThat(set.subSet(3, 3)).isEmpty();
    assertThat(set.subSet(2, 3)).containsExactly(2).inOrder();
    assertThat(set.subSet(1, 3)).containsExactly(1, 2).inOrder();

    SortedSet<String> set = of("e");
    assertTrue(set.subSet("c", "g") instanceof ImmutableSortedSet);
    assertThat(set.subSet("c", "g")).contains("e");
    assertThat(set.subSet("e", "g")).contains("e");
    assertSame(this.<String>of(), set.subSet("f", "g"));
    assertSame(this.<String>of(), set.subSet("c", "e"));
    assertSame(this.<String>of(), set.subSet("c", "d"));
  }

  public void testSingle_first() {

  }

  @Override
  public ContiguousSet<C> subSet(C fromElement, C toElement) {
    checkNotNull(fromElement);
    checkNotNull(toElement);
    checkArgument(comparator().compare(fromElement, toElement) <= 0);
    return subSetImpl(fromElement, true, toElement, false);
  }

  /** @since 12.0 */
  @GwtIncompatible // NavigableSet
  @Override
  public ContiguousSet<C> subSet(