public static <E> Collector<E, ?, ImmutableSet<E>> toImmutableSet() {
    return CollectCollectors.toImmutableSet();
  }

  /**
   * Returns the empty immutable set. Preferred over {@link Collections#emptySet} for code
   * consistency, and because the return type conveys the immutability guarantee.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */

        There is always *some* alternative to adding a new feature to Guava, even if it's just
        forking Guava yourself.


        We want to see that new features have some significant advantage over the alternatives.
        These advantages can take
        [many forms](https://github.com/google/guava/wiki/PhilosophyExplained#utility), but taking

        ShareEnumIterator it = new ShareEnumIterator(parent, entries.iterator(), null);

        // hasNext/next sequence over two elements
        assertTrue(it.hasNext(), "Expected first element available");
        SmbResource r1 = it.next();
        assertNotNull(r1);

   * given list. Only objects present in the list (according to {@link Object#equals}) may be
   * compared. This comparator imposes a "partial ordering" over the type {@code T}. Subsequent
   * changes to the {@code valuesInOrder} list will have no effect on the returned comparator. Null
   * values in the list are not supported.
   *

  @Synchronized
  fun runningCallsCount(): Int = runningAsyncCalls.size + runningSyncCalls.size

  @JvmName("-deprecated_executorService")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "executorService"),
    level = DeprecationLevel.ERROR,
  )
  fun executorService(): ExecutorService = executorService

   * java.util.NoSuchElementException NoSuchElementException}.
   *
   * @throws IllegalStateException if the instance is absent ({@link #isPresent} returns {@code
   *     false}); depending on this <i>specific</i> exception type (over the more general {@link
   *     RuntimeException}) is discouraged
   */
  public abstract T get();

  /**
   * Returns the contained instance if it is present; {@code defaultValue} otherwise. If no default

            if (pos != -1) {
                buf.replace(pos, pos + 1, "ss");
            }
        }
        return new String(buf);
    }

    /**
     * An {@link Iterator} that iterates over {@link DateFormat} instances corresponding to the styles supported by the locale.
     *
     * @author koichik
     */
    protected static class DateFormatIterator implements Iterator<DateFormat> {

            if (pos != -1) {
                buf.replace(pos, pos + 1, "ss");
            }
        }
        return new String(buf);
    }

    /**
     * An {@link Iterator} that iterates over {@link DateFormat} instances corresponding to the styles supported by the locale.
     *
     * @author koichik
     */
    protected static class DateFormatIterator implements Iterator<DateFormat> {

    Client->>Proxy: HTTPS Request<br/>Host: mysuperapp.com<br/>Path: /items

    Note over Proxy: Proxy adds forwarded headers

    Proxy->>Server: HTTP Request<br/>X-Forwarded-For: [client IP]<br/>X-Forwarded-Proto: https<br/>X-Forwarded-Host: mysuperapp.com<br/>Path: /items

    Note over Server: Server interprets headers<br/>(if --forwarded-allow-ips is set)

    Client->>Proxy: HTTPS Request<br/>Host: mysuperapp.com<br/>Path: /items

    Note over Proxy: Proxy adds forwarded headers

    Proxy->>Server: HTTP Request<br/>X-Forwarded-For: [client IP]<br/>X-Forwarded-Proto: https<br/>X-Forwarded-Host: mysuperapp.com<br/>Path: /items

    Note over Server: Server interprets headers<br/>(if --forwarded-allow-ips is set)