code: public static Update updatePojo(Object pojo) {
        Objects.requireNonNull(pojo, "Pojo cannot be null");
  
        ObjectNode set = JsonNodeFactory.instance.objectNode();
        JsonNode pojoAsJson = JSON.toJsonNode(pojo);
        if (!(pojoAsJson instanceof ObjectNode)) {
          throw new IllegalArgumentException(pojo+" is not a pojo!");
        }
        set.set("$set", pojoAsJson);
        return new Update(set);
      }
docs: Creates an update like so: $set: toJson(pojo)
  
  @param pojo
  @return