table = (BitSet) table.clone();
        // If only we could actually call BitSet.trimToSize() ourselves...
      }
      this.table = table;
    }

    @Override
    public boolean matches(char c) {
      return table.get(c);
    }

    @Override
    void setBits(BitSet bitSet) {
      bitSet.or(table);
    }
  }

  // Static constant implementation classes

        }
        return false;
      }

      @Override
      public Iterator<Set<E>> iterator() {
        return new AbstractIterator<Set<E>>() {
          final BitSet bits = new BitSet(index.size());

          @Override
          protected @Nullable Set<E> computeNext() {
            if (bits.isEmpty()) {
              bits.set(0, size);
            } else {