public void clear() {
      biMap.clear();
    }
  }

  @LazyInit private transient Set<K> keySet;

  @Override
  public Set<K> keySet() {
    Set<K> result = keySet;
    return (result == null) ? keySet = new KeySet() : result;
  }

  final class KeySet extends View<K, V, K> {
    KeySet() {
      super(HashBiMap.this);
    }

    @Override
    @ParametricNullness

    }

    @Override
    public int hashCode() {
      return standardHashCode();
    }

    @Override
    public Set<K> keySet() {
      /*
       * We can't use StandardKeySet, as NavigableMapTestSuiteBuilder assumes that our keySet is a
       * NavigableSet. We test StandardKeySet in the superclass, so it's still covered.
       */
      return navigableKeySet();
    }

    @Override

    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.keySet().removeAll(null) doesn't throws NPE.
    }
  }

  @Override
  public void testKeySetRetainAllNullFromEmpty() {
    try {
      super.testKeySetRetainAllNullFromEmpty();
    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.keySet().retainAll(null) doesn't throws NPE.
    }
  }

  @Override

    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.keySet().removeAll(null) doesn't throws NPE.
    }
  }

  @Override
  public void testKeySetRetainAllNullFromEmpty() {
    try {
      super.testKeySetRetainAllNullFromEmpty();
    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.keySet().retainAll(null) doesn't throws NPE.
    }
  }

  @Override

    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.keySet().removeAll(null) doesn't throws NPE.
    }
  }

  @Override
  public void testKeySetRetainAllNullFromEmpty() {
    try {
      super.testKeySetRetainAllNullFromEmpty();
    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.keySet().retainAll(null) doesn't throws NPE.
    }
  }

  @Override

boolean remove(Object); } org/codehaus/plexus/util/FastMap$KeySet$1.class package org.codehaus.plexus.util; synchronized class FastMap$KeySet$1 implements java.util.Iterator { FastMap$EntryImpl after; FastMap$EntryImpl before; void FastMap$KeySet$1(FastMap$KeySet); public void remove(); public boolean hasNext(); public Object next(); } org/codehaus/plexus/util/FastMap$KeySet.class package org.codehaus.plexus.util; synchronized class FastMap$KeySet extends java.util.AbstractSet { private void FastMap$KeySet(FastMap);...

    this(new TreeMap<K, V>(map));
  }

  private SafeTreeMap(NavigableMap<K, V> delegate) {
    this.delegate = delegate;
    if (delegate == null) {
      throw new NullPointerException();
    }
    for (K k : keySet()) {
      checkValid(k);
    }
  }

  @Override
  public @Nullable Entry<K, V> ceilingEntry(K key) {
    return delegate.ceilingEntry(checkValid(key));
  }

  @Override

    this(new TreeMap<K, V>(map));
  }

  private SafeTreeMap(NavigableMap<K, V> delegate) {
    this.delegate = delegate;
    if (delegate == null) {
      throw new NullPointerException();
    }
    for (K k : keySet()) {
      checkValid(k);
    }
  }

  @Override
  public @Nullable Entry<K, V> ceilingEntry(K key) {
    return delegate.ceilingEntry(checkValid(key));
  }

  @Override

        }

    }

    protected void testUpdate() {
        // Test: update settings api
        final Set<String> keySet = createTestParam(0).keySet();
        final Map<String, Object> updateMap = getUpdateMap();
        final Map<String, Object> searchBody = createSearchBody(SEARCH_ALL_NUM);
        List<Map<String, Object>> settings = getItemList(searchBody);

        System.getProperties().keySet().stream().filter(k -> k != null && k.toString().startsWith(Constants.FESS_CONFIG_PREFIX))
                .forEach(k -> addSystemProperty(cmdList, k.toString(), null, null));
    }

    protected void addFessSystemProperties(final List<String> cmdList) {