}
    }

    public void addExtractor(final List<String> keyList, final Extractor extractor) {
        if (keyList == null || keyList.isEmpty()) {
            throw new CrawlerSystemException("The key list is empty.");
        }
        for (final String key : keyList) {
            addExtractor(key, extractor);
        }
    }

    public Extractor getExtractor(final String key) {
        return extractorMap.get(key);

	if isDirEmpty(dir2, true) {
		t.Error("expected false for a file, got true")
	}

	// Should give true for a real empty directory.
	dir3 := slashpath.Join(tmp, "empty")
	err = os.Mkdir(dir3, 0o777)
	if err != nil {
		t.Fatal(err)
	}

	if !isDirEmpty(dir3, true) {
		t.Error("expected true for empty dir, got false")
	}
}

func TestXLStorageReadVersionLegacy(t *testing.T) {

@ElementTypesAreNonnullByDefault
class CompactHashSet<E extends @Nullable Object> extends AbstractSet<E> implements Serializable {
  // TODO(user): cache all field accesses in local vars

  /** Creates an empty {@code CompactHashSet} instance. */
  public static <E extends @Nullable Object> CompactHashSet<E> create() {
    return new CompactHashSet<>();
  }

  /**

    public CharSource asCharSource(Charset charset) {
      checkNotNull(charset);
      return CharSource.empty();
    }

    @Override
    public byte[] read() {
      return bytes; // length is 0, no need to clone
    }

    @Override
    public String toString() {
      return "ByteSource.empty()";
    }
  }

  private static final class ConcatenatedByteSource extends ByteSource {

}

// DeleteMarkerMTime is an embedded type containing time.Time for XML marshal
type DeleteMarkerMTime struct {
	time.Time
}

// MarshalXML encodes expiration date if it is non-zero and encodes
// empty string otherwise
func (t DeleteMarkerMTime) MarshalXML(e *xml.Encoder, startElement xml.StartElement) error {
	if t.Time.IsZero() {
		return nil
	}
	return e.EncodeElement(t.Time.Format(time.RFC3339), startElement)
}

	return rulesMap[eventName].Match(objectName)
}

// NewRulesMap - creates new rules map with given values.
func NewRulesMap(eventNames []Name, pattern string, targetID TargetID) RulesMap {
	// If pattern is empty, add '*' wildcard to match all.
	if pattern == "" {
		pattern = "*"
	}

	rulesMap := make(RulesMap)
	rulesMap.add(eventNames, pattern, targetID)
	return rulesMap

     * exception is thrown so this information is merely meant to assist the user.
     *
     * @return The identifier of the POM or an empty string if not known, never {@code null}.
     */
    public String getModelId() {
        if (result == null) {
            return "";
        } else if (result.getEffectiveModel() != null) {

            if (dictFile.getId().equals(id)) {
                return OptionalEntity.of(dictFile);
            }
        }
        return OptionalEntity.empty();
    }

    public void store(final DictionaryFile<? extends DictionaryItem> dictFile, final File file) {
        getDictionaryFile(dictFile.getId()).ifPresent(currentFile -> {

     */
    @Nonnull
    InputStream openStream() throws IOException;

    /**
     * Provides a user-friendly hint about the location of the source.
     * This could be a local file path, a URI or just an empty string.
     * The intention is to assist users during error reporting.
     *
     * @return a user-friendly hint about the location of the source, never {@code null}
     */
    @Nonnull
    String getLocation();

			expectedFields: map[string]struct{}{
				`connection_string="host=localhost port=2832"`: {},
				`comment="really long comment"`:                {},
			},
		},
		// Incorrect delimiter, expected fields should be empty.
		{
			input:          `comment:"really long comment" connection_string:"host=localhost port=2832"`,
			keys:           []string{"connection_string", "comment"},
			expectedFields: map[string]struct{}{},
		},