code: public List<String> getStringListFromCluster(final String key) {
      List<String> curlist = getStringList(key, "\\s*;\\s*");
      // remove empty elements in the array
      for (Iterator<String> iter = curlist.listIterator(); iter.hasNext(); ) {
        String a = iter.next();
        if (a.length() == 0) {
          iter.remove();
        }
      }
      return curlist;
    }
docs: Returns a list of clusters with the comma as the separator of the value
  e.g., for input string: "thrift://hcat1:port,thrift://hcat2:port;thrift://hcat3:port,thrift://hcat4:port;"
  we will get ["thrift://hcat1:port,thrift://hcat2:port", "thrift://hcat3:port,thrift://hcat4:port"]
  as output