code: @Override
      public List<PluginData> getPluginData() {
          List<PluginData> results = new ArrayList<>();
          for (Field field : getClass().getDeclaredFields()) {
              if (field.isAnnotationPresent(Plugin.Data.class)) {
                  String fileName = getFileName(field);
                  results.add(new PluginData(fileName, getFieldValue(field)));
              }
          }
          return results;
      }
docs: This method creates a {@link PluginData} for each field with
  {@link Plugin.Data} annotation.
  
  @see #getFileName(Field)
  @see #getFieldValue(Field)