code: public byte[] toByteArray()
      {
          int length = getLength() + 1;
          byte result[] = new byte[length];
          System.arraycopy(m_key_, 0, result, 0, length);
          return result;
      }
docs: Duplicates and returns the value of this CollationKey as a sequence
  of big-endian bytes terminated by a null.
  
  <p>If two CollationKeys can be legitimately compared, then one can
  compare the byte arrays of each to obtain the same result, e.g.
  <pre>
  byte key1[] = collationkey1.toByteArray();
  byte key2[] = collationkey2.toByteArray();
  int key, targetkey;
  int i = 0;
  do {
  key = key1[i] &amp; 0xFF;
  targetkey = key2[i] &amp; 0xFF;
  if (key &lt; targetkey) {
  System.out.println("String 1 is less than string 2");
  return;
  }
  if (targetkey &lt; key) {
  System.out.println("String 1 is more than string 2");
  }
  i ++;
  } while (key != 0 &amp;&amp; targetKey != 0);
  
  System.out.println("Strings are equal.");
  </pre>
  
  @return CollationKey value in a sequence of big-endian byte bytes
  terminated by a null.