code: private List<String> hashtagsFromArray(JSONObject json, String array) {
          if (json.containsKey(array)) {
              JSONArray hashtagsArray = json.getJSONArray(array);
              List<String> result = new ArrayList<String>(hashtagsArray.size());
              for (Object tag : hashtagsArray) {
                  result.add(tag.toString());
              }
              return result;
          }
          return Collections.emptyList();
      }
docs: Converts an array key from JSON into a list of the strings it contains.
  
  @param json The json object.
  @param array The array name within the json object.
  @return A list of strings contained in the array or an empty list if the array is not present.