code: public static Map<String, Object> jsonMap(JsonReader reader) throws IOException {
          Map<String, Object> map = new HashMap<>();
          reader.beginObject();
          while (reader.hasNext() && reader.peek() == JsonToken.NAME) {
              String name = reader.nextName();
              Object value = jsonValue(reader);
              if (value != null) {
                  map.put(name, value);
              }
          }
          reader.endObject();
          return map;
      }
docs: Transforms a JSON object (stream) into a Map object.