code: @SuppressWarnings("unchecked")
    private void mergeConfigs(Map<String, Map<String, ?>> configurationMap,
        Object parsed) {
      if(parsed instanceof Map) {
        Map<?, ?> parsedMap = (Map<?, ?>) parsed;
        for(Object key : parsedMap.keySet()) {
          if(key instanceof String) {
            Map<String, Object> existingValue = (Map<String, Object>) configurationMap.get((String) key);
            if(!configurationMap.containsKey((String) key)) {
              existingValue = new HashMap<String, Object>();
              configurationMap.put((String) key, existingValue);
            }
            Object parsedValue = parsedMap.get(key);
            if(parsedValue instanceof Map) {
              Map<?, ?> parsedValueMap = (Map<?, ?>) parsedValue;
              for(Object parsedKey : parsedValueMap.keySet()) {
                if(parsedKey instanceof String) {
                  existingValue.put((String) parsedKey, parsedValueMap.get(parsedKey));
                }
              }
            }
          }
        }
      }
    }
docs: Merges configurations from an Object into an existing Map.
  
  @param configurationMap
  @param parsed