code: public static <K, V> HashMap<K, V> newHashMap(Map<? extends K, ? extends V> map) {
      return new HashMap<>(map);
    }
docs: Creates a <i>mutable</i> {@code HashMap} instance with the same mappings as the specified map.
  
  <p><b>Note:</b> if mutability is not required, use {@link ImmutableMap#copyOf(Map)} instead.
  
  <p><b>Note:</b> if {@code K} is an {@link Enum} type, use {@link #newEnumMap} 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 HashMap} constructor directly, taking advantage of the new
  <a href="http://goo.gl/iz2Wi">"diamond" syntax</a>.
  
  @param map the mappings to be placed in the new map
  @return a new {@code HashMap} initialized with the mappings from {@code map}