// every mode except UNNECESSARY
      BigDecimal expected = new BigDecimal(d).setScale(0, UNNECESSARY);
      boolean isInBounds =
          expected.compareTo(MAX_LONG_AS_BIG_DECIMAL) <= 0
              & expected.compareTo(MIN_LONG_AS_BIG_DECIMAL) >= 0;

      try {
        assertEquals(expected.longValue(), DoubleMath.roundToLong(d, UNNECESSARY));
        assertTrue(isInBounds);

   * @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
   *     is not a power of two
   */
  @SuppressWarnings("fallthrough")
  // TODO(kevinb): remove after this warning is disabled globally
  public static int log2(int x, RoundingMode mode) {
    checkPositive("x", x);
    switch (mode) {
      case UNNECESSARY:
        checkRoundingUnnecessary(isPowerOfTwo(x));
      // fall through

   *     is not a power of two
   */
  @SuppressWarnings("fallthrough")
  // TODO(kevinb): remove after this warning is disabled globally
  public static int log2(BigInteger x, RoundingMode mode) {
    checkPositive("x", checkNotNull(x));
    int logFloor = x.bitLength() - 1;
    switch (mode) {
      case UNNECESSARY:

      if (!expectedValues.containsKey(UNNECESSARY)) {
        assertWithMessage("Expected roundUnnecessaryShouldThrow call")
            .that(unnecessaryShouldThrow)
            .isTrue();
        assertThrows(
            "Expected ArithmeticException for roundToDouble(" + input + ", UNNECESSARY)",
            ArithmeticException.class,
            () -> BigDecimalMath.roundToDouble(input, UNNECESSARY));
      }
    }
  }

import static java.lang.Math.min;
import static java.math.BigInteger.valueOf;
import static java.math.RoundingMode.DOWN;
import static java.math.RoundingMode.FLOOR;
import static java.math.RoundingMode.UNNECESSARY;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.testing.NullPointerTester;

      } catch (ArithmeticException expected) {
        // do nothing
      }

      if (expectedDouble != null) {
        assertThat(LongMath.roundToDouble(candidate, UNNECESSARY)).isEqualTo(expectedDouble);
      } else {
        assertThrows(
            ArithmeticException.class, () -> LongMath.roundToDouble(candidate, UNNECESSARY));
      }
    }
  }

   * </ul>
   *
   * <p>This assumes that any non-null objects passed to this function conform to the {@code
   * equals()} contract.
   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated; use {@link
   * java.util.Objects#equals} instead.
   */
  @SuppressWarnings("InlineMeSuggester") // would introduce fully qualified references to Objects

import static java.lang.Math.min;
import static java.math.BigInteger.valueOf;
import static java.math.RoundingMode.DOWN;
import static java.math.RoundingMode.FLOOR;
import static java.math.RoundingMode.UNNECESSARY;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.testing.NullPointerTester;

        case UP:
          return roundArbitrarily;
        case UNNECESSARY:
          throw new ArithmeticException(x + " cannot be represented precisely as a double");
      }
    }
    X roundArbitrarilyAsX = toX(roundArbitrarily, RoundingMode.UNNECESSARY);
    int cmpXToRoundArbitrarily = x.compareTo(roundArbitrarilyAsX);
    switch (mode) {
      case UNNECESSARY:
        checkRoundingUnnecessary(cmpXToRoundArbitrarily == 0);

  static double roundIntermediate(double x, RoundingMode mode) {
    if (!isFinite(x)) {
      throw new ArithmeticException("input is infinite or NaN");
    }
    switch (mode) {
      case UNNECESSARY:
        checkRoundingUnnecessary(isMathematicalInteger(x));
        return x;

      case FLOOR:
        if (x >= 0.0 || isMathematicalInteger(x)) {
          return x;
        } else {