@Nonnull
 public final EChange putAllIn(@Nonnull final Map<? extends KEYTYPE, ? extends VALUETYPE> aMap) {
   EChange eChange = EChange.UNCHANGED;
   for (final Map.Entry<? extends KEYTYPE, ? extends VALUETYPE> aEntry : aMap.entrySet())
     eChange = eChange.or(putSingle(aEntry.getKey(), aEntry.getValue()));
   return eChange;
 }