* java.util.Optional}, or {@code null} if the argument is null.
   *
   * @since 33.4.0 (but since 21.0 in the JRE flavor)
   */
  @SuppressWarnings("NullableOptional") // Null passthrough is reasonable for type conversions
  @IgnoreJRERequirement // Users will use this only if they're already using Optional.
  public static <T> @Nullable Optional<T> fromJavaUtil(

  @LazyInit private @Nullable String toString;

  @LazyInit private int hashCode;

  // We need to differentiate between "not computed" and "computed to be absent."
  @SuppressWarnings("NullableOptional")
  @LazyInit
  private @Nullable Optional<Charset> parsedCharset;

  private MediaType(String type, String subtype, ImmutableListMultimap<String, String> parameters) {
    this.type = type;

  @LazyInit private @Nullable String toString;

  @LazyInit private int hashCode;

  // We need to differentiate between "not computed" and "computed to be absent."
  @SuppressWarnings("NullableOptional")
  @LazyInit
  private @Nullable Optional<Charset> parsedCharset;

  private MediaType(String type, String subtype, ImmutableListMultimap<String, String> parameters) {
    this.type = type;