) {
  /**
   * Returns the charset of this media type, or [defaultValue] if either this media type doesn't
   * specify a charset, or if its charset is unsupported by the current runtime.
   */
  @JvmOverloads
  fun charset(defaultValue: Charset? = null): Charset? {
    val charset = parameter("charset") ?: return defaultValue
    return try {
      Charset.forName(charset)
    } catch (_: IllegalArgumentException) {

            } catch (final NumberFormatException e) {}
        }
        return defaultValue;
    }

    protected String getDefaultString(final String key, final String defaultValue) {
        final String value = systemProperties.getProperty(key);
        if (value != null) {
            return value;
        }
        return defaultValue;
    }

    protected boolean isWebCrawlingPath(final String path) {

        override val currentFile: File,

        override val currentSourceRoot: File

    ) : ApiSourceFile()
}


internal
data class JavaSourceQuery<T : Any?>(
    val defaultValue: T,
    val visitor: GenericVisitor<T, Unit?>
)


internal
class SourcesRepository(

    private
    val sourceRoots: List<File>,

    private
    val compilationClasspath: List<File>

   * position}th position or {@code defaultValue} otherwise.
   *
   * @param position position of the element to return
   * @param defaultValue the default value to return if the iterator is empty or if {@code position}
   *     is greater than the number of elements remaining in {@code iterator}
   * @return the element at the specified position in {@code iterator} or {@code defaultValue} if

          <name>type</name>
          <version>4.0.0+</version>
          <defaultValue>mail</defaultValue>
          <type>String</type>
          <description>The mechanism used to deliver notifications.</description>
        </field>
        <field>
          <name>sendOnError</name>
          <version>4.0.0+</version>
          <defaultValue>true</defaultValue>
          <type>boolean</type>

        }
    }

    protected <T> T getInitParameter(final String key, final T defaultValue, final Class<T> clazz) {
        if (initParamMap != null) {
            try {
                final Object paramValue = initParamMap.get(key);
                if (paramValue == null) {
                    return defaultValue;
                }

                return convertObj(paramValue, clazz);

          <version>1.0.0+</version>
          <description>Whether to use a local copy instead (with filename that includes the base version)</description>
          <type>boolean</type>
          <defaultValue>false</defaultValue>
        </field>
      </fields>
    </class>
    <class java.clone="deep">
      <name>SnapshotVersion</name>
      <version>1.1.0+</version>

  }

  @Override
  public boolean isPresent() {
    return true;
  }

  @Override
  public T get() {
    return reference;
  }

  @Override
  public T or(T defaultValue) {
    checkNotNull(defaultValue, "use Optional.orNull() instead of Optional.or(null)");
    return reference;
  }

  @Override
  public Optional<T> or(Optional<? extends T> secondChoice) {
    checkNotNull(secondChoice);

            if (appendValue != null) {
                buf.append(appendValue);
            }
            cmdList.add(buf.toString());
        } else if (defaultValue != null) {
            cmdList.add("-D" + name + "=" + defaultValue);
        }
    }

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

    }

    @Override
    public Path getPath() {
        return artifact.getPath();
    }

    @Override
    public String getProperty(String key, String defaultValue) {
        return artifact.getProperty(key, defaultValue);
    }

    @Override
    public Map<String, String> getProperties() {
        return artifact.getProperties();
    }

    public String getMessage() {