@Test
  public void testHashCode() {
    String s = "test";
    Integer i = new Integer(245);
    Double d = new Double(2.4);
    Object[] objs = new Object[3];
    objs[0] = s;
    objs[1] = i;
    objs[2] = d;
    int code1 = Utils.hashcode(objs);
    int code2 = Utils.hashcode(objs);
    Assert.assertEquals(code1, code2);
  }
Return the internal byte array of the given {@link ByteBuffer}. It only works when the {@link ByteBuffer} is not
a direct {@link ByteBuffer}.
@param buffer The {@link ByteBuffer}.
@return The internal byte array.
@throws Exception Any unexpected error.
ambry-utils/src/test/java/com/github/ambry/utils/UtilsTest.java