* the result set is constructed, the input set is merely copied. Only as the result set is
   * iterated are the individual subsets created. Each of these subsets occupies an additional O(n)
   * memory but only for as long as the user retains a reference to it. That is, the set returned by
   * {@code combinations} does not retain the individual subsets.
   *
   * @param set the set of elements to take combinations of

    }
  }

  /**
   * Creates an executor service that runs each task in the thread that invokes {@code
   * execute/submit}, as in {@code ThreadPoolExecutor.CallerRunsPolicy}. This applies both to
   * individually submitted tasks and to collections of tasks submitted via {@code invokeAll} or
   * {@code invokeAny}. In the latter case, tasks will run serially on the calling thread. Tasks are

  /**
   * The HTTP <a href="https://patcg-individual-drafts.github.io/topics/">{@code
   * Sec-Browsing-Topics}</a> header field name.
   *
   * @since 32.0.0
   */
  public static final String SEC_BROWSING_TOPICS = "Sec-Browsing-Topics";
  /**
   * The HTTP <a href="https://patcg-individual-drafts.github.io/topics/">{@code
   * Observe-Browsing-Topics}</a> header field name.
   *

   * meet the contract guaranteed by this method.
   *
   * <p>There is no {@link Iterable} equivalent to this method, so use this method to wrap each
   * individual iterator as it is generated.
   *
   * @param iterator the backing iterator. The {@link PeekingIterator} assumes ownership of this
   *     iterator, so users should cease making direct calls to it after calling this method.