if (o instanceof Entry) {
        Entry<?, ?> entry = (Entry<?, ?>) o;
        if (unfiltered.containsKey(entry.getKey())
            // if this holds, then we know entry.getKey() is a K
            && keyPredicate.apply((K) entry.getKey())) {
          return unfiltered.remove(entry.getKey(), entry.getValue());
        }
      }
      return false;
    }
  }

  @Override

      this.samples =
          new SampleElements<>(
              mapSamples.e0().getKey(),
              mapSamples.e1().getKey(),
              mapSamples.e2().getKey(),
              mapSamples.e3().getKey(),
              mapSamples.e4().getKey());
    }

    @Override
    public SampleElements<K> samples() {
      return samples;
    }

    @Override

    Entry<String, Collection<Integer>> entry = iterator.next();
    assertEquals("foo", entry.getKey());
    assertThat(entry.getValue()).containsExactly(1, 3, 7);
    entry = iterator.next();
    assertEquals("google", entry.getKey());
    assertThat(entry.getValue()).containsExactly(2, 6);
    entry = iterator.next();
    assertEquals("tree", entry.getKey());
    assertThat(entry.getValue()).containsExactly(0, 4);
  }

    Entry<K, V> secondEntry = iterator.next();
    K key = secondEntry.getKey();
    SortedMap<K, V> subMap = map.tailMap(key);
    V value = getValueNotInPopulatedMap();
    subMap.put(key, value);
    assertEquals(secondEntry.getValue(), value);
    assertEquals(map.get(key), value);
    assertThrows(IllegalArgumentException.class, () -> subMap.put(firstEntry.getKey(), value));
  }

  public void testTailMapRemoveThrough() {

    Entry<K, V> secondEntry = iterator.next();
    K key = secondEntry.getKey();
    SortedMap<K, V> subMap = map.tailMap(key);
    V value = getValueNotInPopulatedMap();
    subMap.put(key, value);
    assertEquals(secondEntry.getValue(), value);
    assertEquals(map.get(key), value);
    assertThrows(IllegalArgumentException.class, () -> subMap.put(firstEntry.getKey(), value));
  }

  public void testTailMapRemoveThrough() {

    }

    /**
     * Returns the key.
     *
     * @return the key
     */
    public String getKey() {
        return key;
    }

    /**
     * Sets the key.
     *
     * @param key
     *            the key
     */
    public void setKey(final String key) {
        this.key = key;
    }

    /**
     * Returns the charset name.
     *

      while (true) {
        if (entryIterator.hasNext()) {
          Entry<C, V> entry = entryIterator.next();
          if (!seen.containsKey(entry.getKey())) {
            seen.put(entry.getKey(), entry.getValue());
            return entry.getKey();
          }
        } else if (mapIterator.hasNext()) {
          entryIterator = mapIterator.next().entrySet().iterator();
        } else {

      int expectedEntrySetHash = 0;
      for (Entry<K, V> entry : entrySet) {
        assertTrue(map.containsKey(entry.getKey()));
        assertTrue(map.containsValue(entry.getValue()));
        int expectedHash =
            (entry.getKey() == null ? 0 : entry.getKey().hashCode())
                ^ (entry.getValue() == null ? 0 : entry.getValue().hashCode());
        assertEquals(expectedHash, entry.hashCode());

        public int compare(Entry<AnEnum, String> left, Entry<AnEnum, String> right) {
          return left.getKey().compareTo(right.getKey());
        }
      }.sortedCopy(insertionOrder);
    }
  }

  public static class ImmutableMapValuesAsSingletonSetGenerator
      implements TestMapGenerator<String, Collection<Integer>> {

    @Override
    public SampleElements<Entry<String, Collection<Integer>>> samples() {

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testSetValue_valueAbsent() {
    for (Entry<K, V> entry : getMap().entrySet()) {
      if (entry.getKey().equals(k0())) {
        assertEquals("entry.setValue() should return the old value", v0(), entry.setValue(v3()));
      }
    }
    expectReplacement(entry(k0(), v3()));
  }

  @MapFeature.Require(SUPPORTS_PUT)