code: private static boolean checkDuplicate(String muri,processNAFVariables vars) {
          boolean re = false;        
         for(String keys:vars.entityMentions.keySet()){
              if (keys.equals(muri)) {
              //if (mtmp.getID().stringValue().equals(muri)) {
                  re = true;
                  break;
              }
          }
          return re;
      }
docs: /*
  return true if another mention exists with the same span