// Test all non-escaped ASCII characters.
    String s =
        "!@#$%^*()_+=-/?\\|]}[{,.;:"
            + "abcdefghijklmnopqrstuvwxyz"
            + "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
            + "1234567890";
    assertEquals(s, xmlEscaper.escape(s));

    // Test ASCII control characters.
    for (char ch = 0; ch < 0x20; ch++) {
      if (ch == '\t' || ch == '\n' || ch == '\r') {

    try {
      Ascii.truncate("foobar", 2, "...");
      fail();
    } catch (IllegalArgumentException expected) {
    }

    try {
      Ascii.truncate("foobar", 8, "1234567890");
      fail();
    } catch (IllegalArgumentException expected) {
    }

    try {
      Ascii.truncate("foobar", -1, "...");
      fail();
    } catch (IllegalArgumentException expected) {
    }

  public void testKnownValues() {
    assertSip(new byte[] {}, 0x726fdb47dd0e0e31L);
    assertSip(new byte[] {0x61}, 0x2ba3e8e9a71148caL);
    assertSip(new byte[1000000], 0x28205108397aa742L);
    assertSip("12345678", 0x02130609caea37ebL);
    assertSip("abcdef", 0x2a6e77e733c7c05dL);
    assertSip("SipHash", 0x8325093242a96f60L);
  }

  // Test for common pitfall regarding sign extension.

    }

    try {
      Strings.repeat("x", -1);
      fail();
    } catch (IllegalArgumentException expected) {
    }
    try {
      // Massive string
      Strings.repeat("12345678", (1 << 30) + 3);
      fail();
    } catch (ArrayIndexOutOfBoundsException expected) {
    }
  }

  // TODO: could remove if we got NPT working in GWT somehow
  public void testRepeat_null() {
    try {