case 2:
        return nums.get(start).multiply(nums.get(start + 1));
      case 3:
        return nums.get(start).multiply(nums.get(start + 1)).multiply(nums.get(start + 2));
      default:
        // Otherwise, split the list in half and recursively do this.
        int m = (end + start) >>> 1;
        return listProduct(nums, start, m).multiply(listProduct(nums, m, end));
    }
  }

  /**

                Map.of("_default", List.of("QUERY1")), //
                Set.of("QUERY1"), //
                buildQuery("QUERY1^10"));

        assertQueryContext(

        try {
          BigInteger quotient = BigIntegerMath.divide(p, q, UNNECESSARY);
          BigInteger undone = quotient.multiply(q);
          if (!p.equals(undone)) {
            failFormat("expected %s.multiply(%s) = %s; got %s", quotient, q, p, undone);
          }
          assertTrue(dividesEvenly);
        } catch (ArithmeticException e) {
          assertFalse(dividesEvenly);

        try {
          BigInteger quotient = BigIntegerMath.divide(p, q, UNNECESSARY);
          BigInteger undone = quotient.multiply(q);
          if (!p.equals(undone)) {
            failFormat("expected %s.multiply(%s) = %s; got %s", quotient, q, p, undone);
          }
          assertTrue(dividesEvenly);
        } catch (ArithmeticException e) {
          assertFalse(dividesEvenly);

      for (long b : TEST_LONGS) {
        UnsignedLong aUnsigned = UnsignedLong.fromLongBits(a);
        UnsignedLong bUnsigned = UnsignedLong.fromLongBits(b);
        long expected =
            aUnsigned.bigIntegerValue().multiply(bUnsigned.bigIntegerValue()).longValue();
        UnsignedLong unsignedMul = aUnsigned.times(bUnsigned);
        assertThat(unsignedMul.longValue()).isEqualTo(expected);
      }
    }
  }

      for (long b : TEST_LONGS) {
        UnsignedLong aUnsigned = UnsignedLong.fromLongBits(a);
        UnsignedLong bUnsigned = UnsignedLong.fromLongBits(b);
        long expected =
            aUnsigned.bigIntegerValue().multiply(bUnsigned.bigIntegerValue()).longValue();
        UnsignedLong unsignedMul = aUnsigned.times(bUnsigned);
        assertThat(unsignedMul.longValue()).isEqualTo(expected);
      }
    }
  }

  @AndroidIncompatible // presumably slow
  public void testCheckedMultiply() {
    for (int a : ALL_INTEGER_CANDIDATES) {
      for (int b : ALL_INTEGER_CANDIDATES) {
        BigInteger expectedResult = valueOf(a).multiply(valueOf(b));
        boolean expectedSuccess = fitsInInt(expectedResult);
        try {
          assertEquals(a * b, IntMath.checkedMultiply(a, b));
          assertTrue(expectedSuccess);

              // It's definitely safe to multiply into numerator and denominator.
              numerator *= n;
              denominator *= i;
              numeratorBits += nBits;
            } else {
              // It might not be safe to multiply into numerator and denominator,
              // so multiply (numerator / denominator) into result.

     */
    open fun header(
      name: String,
      value: String,
    ) = commonHeader(name, value)

    /**
     * Adds a header with [name] to [value]. Prefer this method for multiply-valued
     * headers like "Set-Cookie".
     */
    open fun addHeader(
      name: String,
      value: String,
    ) = commonAddHeader(name, value)

  @AndroidIncompatible // presumably slow
  public void testCheckedMultiply() {
    for (int a : ALL_INTEGER_CANDIDATES) {
      for (int b : ALL_INTEGER_CANDIDATES) {
        BigInteger expectedResult = valueOf(a).multiply(valueOf(b));
        boolean expectedSuccess = fitsInInt(expectedResult);
        try {
          assertEquals(a * b, IntMath.checkedMultiply(a, b));
          assertTrue(expectedSuccess);