code: private static Resource[] mergeResource(Resource o, Resource... arr) {
          if(o != null) {
              Resource[] newArray = new Resource[arr.length + 1];
              newArray[0] = o;
              System.arraycopy(arr, 0, newArray, 1, arr.length);
              return newArray;
          }else{
              return arr;
          }
  
      }
docs: private utility for merging Resource varargs
  
  @param o
  @param arr
  @return