}

    @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;

                          return next.getValue();
                        }

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

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

        }
        this.headerFields = null;
        for (final Entry<String, List<String>> property : this.connection.getRequestProperties().entrySet()) {
            final String key = property.getKey();
            final StringBuilder value = new StringBuilder();
            final Iterator<String> values = property.getValue().iterator();
            while (values.hasNext()) {
                value.append(values.next());

    super(delegate);

    ImmutableMap.Builder<V, K> builder = ImmutableMap.builder();
    for (Entry<K, V> entry : delegate.entrySet()) {
      builder.put(entry.getValue(), entry.getKey());
    }
    ImmutableMap<V, K> backwardMap = builder.build();
    this.inverse = new RegularImmutableBiMap<V, K>(backwardMap, this);
  }

          }

          @Override
          public K next() {
            Entry<K, V> entry = entryIterator.next(); // store local reference for thread-safety
            cacheEntry = entry;
            return entry.getKey();
          }
        };
      }

      @Override
      public int size() {
        return backingMap.size();
      }

      @Override
      public boolean contains(@Nullable Object key) {

    super(key, value);
    checkEntryNotNull(key, value);
  }

  // Redeclare methods to make them `final`, just to be extra-safe.

  @Override
  @ParametricNullness
  public final K getKey() {
    return super.getKey();
  }

  @Override
  @ParametricNullness
  public final V getValue() {
    return super.getValue();
  }

  @Override
  @ParametricNullness

      Map<K, V> map, ObjectOutputStream stream) throws IOException {
    stream.writeInt(map.size());
    for (Map.Entry<K, V> entry : map.entrySet()) {
      stream.writeObject(entry.getKey());
      stream.writeObject(entry.getValue());
    }
  }

  /**
   * Populates a map by reading an input stream, as part of deserialization. See {@link #writeMap}
   * for the data format.
   */

        if (metadataMap == null) {
            metadataMap = new HashMap<>();
        }

        ArtifactMetadata m = metadataMap.get(metadata.getKey());
        if (m != null) {
            m.merge(metadata);
        } else {
            metadataMap.put(metadata.getKey(), metadata);
        }
    }

    @Override
    public Collection<ArtifactMetadata> getMetadataList() {
        if (metadataMap == null) {

Sie können eine Datei optional machen, indem Sie Standard-Typannotationen verwenden und den Defaultwert auf `None` setzen:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## `UploadFile` mit zusätzlichen Metadaten

Sie können auch `File()` zusammen mit `UploadFile` verwenden, um zum Beispiel zusätzliche Metadaten zu setzen:

{* ../../docs_src/request_files/tutorial001_03_an_py39.py hl[9,15] *}

                    Map<String, String> map = CompactHashMap.create();
                    for (Entry<String, String> entry : entries) {
                      map.put(entry.getKey(), entry.getValue());
                    }
                    return map;
                  }
                })
            .named("CompactHashMap")
            .withFeatures(
                CollectionSize.ANY,