code: public static <T extends Comparable<? super T>> int compare(final T c1, final T c2) {
          return compare(c1, c2, false);
      }
docs: <p>Null safe comparison of Comparables.
  {@code null} is assumed to be less than a non-{@code null} value.</p>
  
  @param <T> type of the values processed by this method
  @param c1  the first comparable, may be null
  @param c2  the second comparable, may be null
  @return a negative value if c1 &lt; c2, zero if c1 = c2
  and a positive value if c1 &gt; c2