docs: public void putIndexedVariableProperties(String key, List<Map<String, String>> subKeyValues) {
  		checkNotNull(key);
  		checkNotNull(subKeyValues);
  		for (int idx = 0; idx < subKeyValues.size(); idx++) {
  			final Map<String, String> values = subKeyValues.get(idx);
  			for (Map.Entry<String, String> value : values.entrySet()) {
  				put(key + '.' + idx + '.' + value.getKey(), value.getValue());
  			}
  		}
  	}