code: public static <K extends Comparable, V> TreeMap<K, V> newTreeMap() {
      return new TreeMap<K, V>();
    }
docs: Creates a <i>mutable</i>, empty {@code TreeMap} instance using the natural
  ordering of its elements.
  
  <p><b>Note:</b> if mutability is not required, use {@link
  ImmutableSortedMap#of()} instead.
  
  <p><b>Note for Java 7 and later:</b> this method is now unnecessary and
  should be treated as deprecated. Instead, use the {@code TreeMap}
  constructor directly, taking advantage of the new
  <a href="http://goo.gl/iz2Wi">"diamond" syntax</a>.
  
  @return a new, empty {@code TreeMap}