* @since 19.0 (since 1.0 as constant {@code INVISIBLE})
   */
  @Deprecated
  public static CharMatcher invisible() {
    return Invisible.INSTANCE;
  }

  /**
   * Determines whether a character is single-width (not double-width). When in doubt, this matcher
   * errs on the side of returning {@code false} (that is, it tends to assume a character is
   * double-width).
   *

    }.also { expected ->
      assertThat(expected).hasMessage("expected at least 1 part")
    }
  }

  @Test fun `skip preamble`() {
    val multipart =
      """
      |this is the preamble! it is invisible to application code
      |
      |--simple boundary
      |
      |abcd
      |--simple boundary--
      """.trimMargin()
        .replace("\n", "\r\n")

    val parts =
      MultipartReader(

    val array = CharArray(count)
    Arrays.fill(array, c)
    return String(array)
  }

  /**
   * Okio buffers are internally implemented as a linked list of arrays. Usually this implementation
   * detail is invisible to the caller, but subtle use of certain APIs may depend on these internal
   * structures.
   *
   * We make such subtle calls in [okhttp3.internal.ws.MessageInflater] because we try to read a

      }
    };

    abstract boolean isVisible(int modifiers);

    /** Returns {@code true} if {@code member} is visible under {@code this} visibility. */
    final boolean isVisible(Member member) {
      return isVisible(member.getModifiers());
    }

    final Iterable<Method> getStaticMethods(Class<?> cls) {
      ImmutableList.Builder<Method> builder = ImmutableList.builder();

    doTestSetBits(inRange('n', 'q'));
    doTestSetBits(forPredicate(Predicates.equalTo('c')));
    doTestSetBits(CharMatcher.ascii());
    doTestSetBits(CharMatcher.digit());
    doTestSetBits(CharMatcher.invisible());
    doTestSetBits(CharMatcher.whitespace());
    doTestSetBits(inRange('A', 'Z').and(inRange('F', 'K').negate()));
  }

  @GwtIncompatible // java.util.BitSet
  private void doTestSetBits(CharMatcher matcher) {

    doTestSetBits(inRange('n', 'q'));
    doTestSetBits(forPredicate(Predicates.equalTo('c')));
    doTestSetBits(CharMatcher.ascii());
    doTestSetBits(CharMatcher.digit());
    doTestSetBits(CharMatcher.invisible());
    doTestSetBits(CharMatcher.whitespace());
    doTestSetBits(inRange('A', 'Z').and(inRange('F', 'K').negate()));
  }

  @GwtIncompatible // java.util.BitSet
  private void doTestSetBits(CharMatcher matcher) {

	NEG	X5					// b3025040
	NEG	X5, X6					// 33035040
	NEGW	X5					// bb025040
	NEGW	X5, X6					// 3b035040

	// This jumps to the second instruction in the function (the
	// first instruction is an invisible stack pointer adjustment).
	JMP	start					// JMP	2

	JMP	2(PC)					// 6f008000
	JMP	(X5)					// 67800200
	JMP	4(X5)					// 67804200

	// CALL and JMP to symbol are encoded as JAL (using LR or ZERO

   * {@code C}
   *
   * <ul>
   *   <li>All visible static methods are checked such that passing null for any parameter that's
   *       not annotated nullable (according to the rules of {@link NullPointerTester}) should throw
   *       {@link NullPointerException}.
   *   <li>If there is any visible constructor or visible static factory method declared by the

    assertFalse(
        Visibility.PUBLIC.isVisible(VisibilityMethods.class.getDeclaredMethod("privateMethod")));
    assertFalse(
        Visibility.PUBLIC.isVisible(
            VisibilityMethods.class.getDeclaredMethod("packagePrivateMethod")));
    assertFalse(
        Visibility.PUBLIC.isVisible(VisibilityMethods.class.getDeclaredMethod("protectedMethod")));
    assertTrue(

        .url("https://server/robots.txt")
        .build()
    val response =
      Response
        .Builder()
        .request(request)
        .code(401)
        .header("WWW-Authenticate", "Basic realm=\"User Visible Realm\"")
        .protocol(HTTP_2)
        .message("Unauthorized")
        .build()
    val authRequest = authenticator.authenticate(route, response)

    assertEquals(