* returns. This method may be useful when testing the garbage collection mechanism itself, or
   * inhibiting a spontaneous GC initiation in subsequent code.
   *
   * <p>In contrast, a plain call to {@link java.lang.System#gc()} does not ensure finalization
   * processing and may run concurrently, for example, if the JVM flag {@code
   * -XX:+ExplicitGCInvokesConcurrent} is used.
   *

 * applies first-in-first-out tie-breaking to comparable elements. To use it, you would insert a
 * {@code new FIFOEntry(anEntry)} instead of a plain entry object.
 *
 * <pre>{@code
 * class FIFOEntry<E extends Comparable<? super E>> implements Comparable<FIFOEntry<E>> {
 *   static final AtomicLong seq = new AtomicLong();
 *
 *   final long seqNum;

            } else if (lowerPath.endsWith(".ttf")) {
                response.setContentType("font/ttf");
            } else if (lowerPath.endsWith(".txt")) {
                response.setContentType("text/plain");
            } else if (lowerPath.endsWith(".woff")) {
                response.setContentType("font/woff");
            } else if (lowerPath.endsWith(".woff2")) {
                response.setContentType("font/woff2");

   * only contain entries which are already present in the cache.
   *
   * @since 11.0
   */
  /*
   * <? extends Object> is mostly the same as <?> to plain Java. But to nullness checkers, they
   * differ: <? extends Object> means "non-null types," while <?> means "all types."
   */
  ImmutableMap<K, V> getAllPresent(Iterable<? extends Object> keys);

  /**

     * it can be used with collections that may contain null. This collection is a collection of
     * non-null elements, so we can treat it as a plain `Object[]`.
     */
    @SuppressWarnings("nullness")
    Object[] result = ObjectArrays.toArrayImpl(this);
    return result;
  }

  @Override

       *
       * (And I don't believe there's any situation in which we call x.combine(y) when x is a plain
       * ImmutableSet.Builder but y is an ImmutableSortedSet.Builder (or vice versa). Certainly
       * ImmutableSortedSet.Builder.combine() is written as if its argument will never be a plain
       * ImmutableSet.Builder: It casts immediately to ImmutableSortedSet.Builder.)
       */
      copyIfNecessary();

        .addHeader("Content-Type: text/plain")
        .addHeader("Last-Modified: " + formatDate(-2, TimeUnit.HOURS))
        .addHeader("Expires: " + formatDate(-1, TimeUnit.HOURS))
        .build(),
    )
    server.enqueue(
      MockResponse
        .Builder()
        .code(HttpURLConnection.HTTP_NOT_MODIFIED)
        .addHeader("Content-Type: text/plain")
        .addHeader("Content-Encoding: gzip")

    val call =
      client.newCall(
        Request(
          url = server.url("/foo"),
          body =
            object : RequestBody() {
              override fun contentType(): MediaType = "text/plain; charset=utf-8".toMediaType()

              override fun writeTo(sink: BufferedSink) {
                sink.write(postBytes)
              }
            },
        ),
      )

            });
        }

        @Override
        public OptionalThing<String> getSavedPlainText() {
            return OptionalThing.ofNullable(plainText, () -> {
                throw new IllegalStateException("Plain text not found");
            });
        }

        @Override
        public OptionalThing<String> getSavedHtmlText() {
            return OptionalThing.empty();
        }

        @Override

     *
     * Unfortunately, we don't distinguish between these two cases in our public API: Joiner.on(...)
     * and Joiner.on(...).useForNull(...) both declare the same return type: plain Joiner. To ensure
     * that users *can* pass null arguments to Joiner, we annotate it as if it always tolerates null
     * inputs, rather than as if it never tolerates them.
     *