case 0:
                    return emptyMap();
                case 1:
                    Map.Entry<K, V> entry = map.entrySet().iterator().next();
                    return singletonMap(entry.getKey(), entry.getValue());
                default:
                    return new MapN<>(map);
            }
        }
    }

    @SuppressWarnings("unchecked")
    static <K, V> Map<K, V> emptyMap() {

    public boolean equals(@Nullable Object object) {
      assertTrue(Thread.holdsLock(mutex));
      return super.equals(object);
    }

    @Override
    public K getKey() {
      assertTrue(Thread.holdsLock(mutex));
      return super.getKey();
    }

    @Override
    public V getValue() {
      assertTrue(Thread.holdsLock(mutex));
      return super.getValue();
    }

    @Override

        }

        private void putAll(Map<Object, Object> s, Map<Object, Object> t, Object excludeKey) {
            for (Map.Entry<Object, Object> e : t.entrySet()) {
                if (!e.getKey().equals(excludeKey)) {
                    s.put(e.getKey(), e.getValue());
                }
            }
        }

        @Override
        protected void mergePluginContainer_Plugins(

    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  @ParametricNullness
  public K lastKey() {
    Entry<K, V> entry = lastEntry();
    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  public @Nullable Entry<K, V> lowerEntry(@ParametricNullness K key) {

            getWebConfig().getConfigParameterMap(ConfigName.CONFIG)
                    .entrySet()
                    .stream()
                    .filter(e -> e.getKey().startsWith(Config.JCIFS_PREFIX))
                    .forEach(e -> jcifsParams.put(e.getKey(), e.getValue()));
            if (!jcifsParams.isEmpty()) {
                config.setNtlmParameters(jcifsParams);
            }

    Iterator<Entry<K, V>> iterator = multimap().entries().iterator();
    Entry<K, V> entry = iterator.next();
    K key = entry.getKey();
    V value = entry.getValue();
    multimap().removeAll(key);
    assertEquals(key, entry.getKey());
    assertEquals(value, entry.getValue());
  }

        final Iterator entries = requestProperties.entrySet().iterator();
        while (entries.hasNext()) {
            final Map.Entry entry = (Map.Entry) entries.next();
            if (key.equalsIgnoreCase((String) entry.getKey())) {
                entry.setValue(values);
                found = true;
                break;
            }
        }
        if (!found) {
            requestProperties.put(key, values);
        }

    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  @ParametricNullness
  public K lastKey() {
    Entry<K, V> entry = lastEntry();
    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  public @Nullable Entry<K, V> lowerEntry(@ParametricNullness K key) {

                          return next.getValue();
                        }

                        @Override
                        public String getKey() {
                          return next.getKey();
                        }

                        @Override
                        public boolean equals(@Nullable Object obj) {
                          return next.equals(obj);

    }

    @Override
    public boolean matchesRequirements(Map<String, String> requirements) {
        for (Map.Entry<String, String> requirement : requirements.entrySet()) {
            String key = requirement.getKey();

            RequirementMatcher matcher = provides.get(key);

            if (matcher == null) {
                getLog().debug("Toolchain {} is missing required property: {}", this, key);
                return false;