code: public void init() throws Exception {
          try {
              unmarshalAndSetBackingMap();
          }
          //If we get to this point, the JSON file is well-formed, but its structure does not map into PersonDir backingMap generic type - fail fast.
          catch (final ClassCastException ex) {
              throw new BeanCreationException(String.format("The semantic structure of the person attributes JSON config is not correct. Please fix it in this resource: [%s]",
                      this.personAttributesConfigFile.getURI()));
          }
      }
docs: Init method un-marshals JSON representation of the person attributes.