} else if (x > 0) {
      return Long.toString(x, radix);
    } else {
      char[] buf = new char[64];
      int i = buf.length;
      if ((radix & (radix - 1)) == 0) {
        // Radix is a power of two so we can avoid division.
        int shift = Integer.numberOfTrailingZeros(radix);
        int mask = radix - 1;
        do {
          buf[--i] = Character.forDigit(((int) x) & mask, radix);

    }
  }

  // Relies on the correctness of isPowerOfTwo(BigInteger).
  public void testLog2Exact() {
    for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
      // We only expect an exception if x was not a power of 2.
      boolean isPowerOf2 = BigIntegerMath.isPowerOfTwo(x);
      try {
        assertEquals(x, ZERO.setBit(BigIntegerMath.log2(x, UNNECESSARY)));
        assertTrue(isPowerOf2);

    /**
     * 4 32-bit words (interim result)
     */
    private int[] context = new int[4];

    /**
     * Number of bytes processed so far mod. 2 power of 64.
     */
    private long count;

    /**
     * 512 bits input buffer = 16 x 32-bit words holds until reaches 512 bits.
     */
    private byte[] buffer = new byte[BLOCK_LENGTH];

    /**

      if (oldCapacity >= MAXIMUM_CAPACITY) {
        return;
      }

      /*
       * Reclassify nodes in each list to new Map. Because we are using power-of-two expansion, the
       * elements from each bin must either stay at same index, or move with a power of two offset.
       * We eliminate unnecessary node creation by catching cases where old nodes can be reused

"Legal Entity" shall mean the union of the acting entity and all other 
entities that control, are controlled by, or are under common control with 
that entity. For the purposes of this definition, "control" means (i) the 
power, direct or indirect, to cause the direction or management of such 
entity, whether by contract or otherwise, or (ii) ownership of fifty percent 
(50%) or more of the outstanding shares, or (iii) beneficial ownership of 
such entity. 

      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the

      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the

    assertSame(testEquivalence, map.keyEquivalence);
    assertSame(map.valueStrength().defaultEquivalence(), map.valueEquivalence());
  }

  public void testSetConcurrencyLevel() {
    // round up to the nearest power of two

    checkConcurrencyLevel(1, 1);
    checkConcurrencyLevel(2, 2);
    checkConcurrencyLevel(3, 4);
    checkConcurrencyLevel(4, 4);
    checkConcurrencyLevel(5, 8);
    checkConcurrencyLevel(6, 8);

    assertSame(testEquivalence, map.keyEquivalence);
    assertSame(map.valueStrength().defaultEquivalence(), map.valueEquivalence());
  }

  public void testSetConcurrencyLevel() {
    // round up to the nearest power of two

    checkConcurrencyLevel(1, 1);
    checkConcurrencyLevel(2, 2);
    checkConcurrencyLevel(3, 4);
    checkConcurrencyLevel(4, 4);
    checkConcurrencyLevel(5, 8);
    checkConcurrencyLevel(6, 8);

  // are replaced by a single `elements` array but everything else works similarly.

  /**
   * The hashtable object. This can be either:
   *
   * <ul>
   *   <li>a byte[], short[], or int[], with size a power of two, created by
   *       CompactHashing.createTable, whose values are either
   *       <ul>
   *         <li>UNSET, meaning "null pointer"
   *         <li>one plus an index into the entries and elements array