code: @SafeVarargs
      public static <E> List<E> asList(E[]... arrs) {
          int size = 0;
          for (E[] arr : arrs) {
              if (arr == null) {
                  throw new IllegalArgumentException("Null arrays not allowed");
              }
              size += arr.length;
          }
          List<E> result = new ArrayList<>(size);
          addAll(result, arrs);
          return result;
      }
docs: Returns a newly created random access list with the contents of the
  provided arrays.
  
  @param <E> any class.
  @param arrs one or more <code>E[]</code>.
  @return a newly created random access {@link List}.