return sequence.subSequence(0, last + 1).toString();
      }
    }
    return "";
  }

  /**
   * Returns a string copy of the input character sequence, with each group of consecutive matching
   * BMP characters replaced by a single replacement character. For example:
   *
   * {@snippet :
   * CharMatcher.anyOf("eko").collapseFrom("bookkeeper", '-')
   * }
   *

          int headIndex = head.getHash() & newMask;

          // Single node on list
          if (next == null) {
            newTable.set(headIndex, head);
          } else {
            // Reuse the consecutive sequence of nodes with the same target
            // index from the end of the list. tail points to the first
            // entry in the reusable list.
            E tail = head;
            int tailIndex = headIndex;