code: public static void removeReservedNullVaules(JsonObject jsonObject) {
          Set<Map.Entry<String, JsonElement>> entries = jsonObject.entrySet();
          for (Map.Entry<String, JsonElement> entry : entries) {
              if (entry.getValue().isJsonNull()) {
                  jsonObject.remove(entry.getKey());
              }
          }
      }
docs: Removes keys from json object if they have null values. Won't touch fields as users may want to explicitly set them to null
  
  @param jsonObject