get testToFromString() {
    const /** !Object<string, function()> */ testCases = {};

    for (let i = 0; i < TEST_BITS.length; i += 2) {
      testCases[`test${i}`] = () => {
        const vi = Long.fromBits(TEST_BITS[i + 1], TEST_BITS[i]);
        const str = vi.toString(10);
        assertEquals(TEST_STRINGS[i / 2], str);
        assertEquals(TEST_BITS[i], Long.fromString(str, 10).getHighBits());
        assertEquals(TEST_BITS[i + 1], Long.fromString(str, 10).getLowBits());

        for (let radix = 2; radix <= 36; ++radix) {
          const result = vi.toString(radix);
          assertEquals(
              TEST_BITS[i], Long.fromString(result, radix).getHighBits());
          assertEquals(
              TEST_BITS[i + 1], Long.fromString(result, radix).getLowBits());
        }
      };
    }

    return testCases;
  }
Nested test suite for string conversions.