* This method was written by Doug Lea with assistance from members of JCP JSR-166 Expert Group
   * and released to the public domain, as explained at
   * http://creativecommons.org/licenses/publicdomain
   *
   * As of 2010/06/11, this method is identical to the (package private) hash method in OpenJDK 7's
   * java.util.HashMap class.
   */
  // Copied from java/com/google/common/collect/Hashing.java
  private static int smear(int hashCode) {