public void testRemove_empty() {
    assertThrows(NoSuchElementException.class, () -> getQueue().remove());
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testRemove_size1() {
    assertEquals("size1Queue.remove() should return first element", e0(), getQueue().remove());
    expectMissing(e0());
  }

  @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_REMOVE})

      TreeRangeMap.this.putAll(rangeMap);
    }

    @Override
    public void clear() {
      TreeRangeMap.this.remove(subRange);
    }

    @Override
    public void remove(Range<K> range) {
      if (range.isConnected(subRange)) {
        TreeRangeMap.this.remove(range.intersection(subRange));
      }
    }

    @Override
    public RangeMap<K, V> subRangeMap(Range<K> range) {

        toRemove = mapEntry;
        return mapEntry.getKey();
      }

      @Override
      public void remove() {
        checkState(toRemove != null, "no calls to next() since the last call to remove()");
        size -= toRemove.getValue().getAndSet(0);
        backingEntries.remove();
        toRemove = null;
      }
    };
  }

  @Override
  Iterator<Entry<E>> entryIterator() {

    } catch (UnsupportedOperationException expected) {
    }
    assertMultimapRemainsUnmodified(multimap, originalEntries);

    // Test #remove()
    try {
      multimap.remove(sampleKey, sampleValue);
      fail("remove succeeded on unmodifiable multimap");
    } catch (UnsupportedOperationException expected) {
    }
    assertMultimapRemainsUnmodified(multimap, originalEntries);

  public void testRemove_empty() {
    assertThrows(NoSuchElementException.class, () -> getQueue().remove());
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testRemove_size1() {
    assertEquals("size1Queue.remove() should return first element", e0(), getQueue().remove());
    expectMissing(e0());
  }

  @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_REMOVE})

        return parent.listIterator(index);
    }

    @Override
    public Map<String, Object> remove(final int index) {
        return parent.remove(index);
    }

    @Override
    public boolean remove(final Object o) {
        return parent.remove(o);
    }

    @Override
    public boolean removeAll(final Collection<?> c) {
        return parent.removeAll(c);
    }

      return delegate.poll();
    }

    @Override
    public E remove() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove();
    }

    @Override
    public boolean remove(Object object) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove(object);
    }

    @Override
    public @Nullable E peek() {

    }

    /**
     * @throws Exception
     */
    @Test
    public void testRemove() throws Exception {
        assertThat(map.remove("1"), is("test"));
        assertThat(map.size(), is(2));
        assertThat(map.remove("dummy"), is(nullValue()));
        assertThat(map.remove(0), is(nullValue()));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testRemove2() throws Exception {

    map.remove("a");
    assertFalse(underlying.containsKey("a"));

    Set<String> keys = map.keySet();
    keys.remove("b");
    assertFalse(underlying.containsKey("b"));

    Iterator<String> keyIterator = keys.iterator();
    keyIterator.next();
    keyIterator.remove();
    assertFalse(underlying.containsKey("c"));

    }
    alertListenerIfPresent(key, oldValue.getValue(), RemovalCause.REPLACED);
    return oldValue.getValue();
  }

  @CanIgnoreReturnValue
  @Override
  public V remove(Object key) {
    Timestamped<V> stamped = cachingHashMap.remove(key);
    if (stamped != null) {
      V value = stamped.getValue();
      // `key` was in the cache, so it's a K.