code: protected void parseGroupMap(Map<String,Object> groupMap, Map<String,String> resultMap, String prefix) {
          Object obj;
          for (String groupKey : groupMap.keySet()) {
              obj = groupMap.get(groupKey);
              String key = prefix == null ? groupKey : prefix + "." + groupKey;
              if (obj instanceof Map)
                  parseGroupMap(loader.getMap(groupKey, groupMap), resultMap, key); // Parse inner map
              else
                  resultMap.put(key, decryptValue(obj.toString())); // String, Boolean and List values
          }
      }
docs: Flattens the group map