docs: public String makeFullPath(String prefix, String... name) {
          StringBuilder sb=new StringBuilder(prefix == null ? "/" : (prefix.equals("/")?prefix:prefix+"/"));
          boolean first=true;
          for (String s : name) {
              if(s==null) continue;
              if(!first){
                  sb.append("/");
              }else
                  first=false;
              sb.append(s);
          }
          return sb.toString();
      }