code: public static long[] longArrayWrappedOrCopy(CollectionNumber coll) {
          long[] array = wrappedLongArray(coll);
          if (array != null) {
              return array;
          }
          return longArrayCopyOf(coll);
      }
docs: Returns either the wrapped array (if exists and matches the type)
  or a copy - USE WITH CAUTION AS IT MAY EXPOSE THE INTERNAL STATE
  OF THE COLLECTION.
  
  @param coll the collection
  @return the array