code: @Override
      public Object transform( Object input ) {
  
          rootSpec.apply( ROOT_KEY, Optional.of( input ), new WalkedPath(), null, null );
  
          return input;
      }
docs: Applies the Cardinality transform.
  
  @param input the JSON object to transform
  @return the output object with data shifted to it
  @throws com.bazaarvoice.jolt.exception.TransformException for a malformed spec or if there are issues during
  the transform