docs: public ConfigurationUpdate add(String path, String key, String value) {
  		if (path == null || !path.startsWith("/")) {
  			throw new IllegalArgumentException("Path must start with \"/\".");
  		}
  		@SuppressWarnings("PMD.UseConcurrentHashMap")
  		Map<String,String> scoped = paths
  				.computeIfAbsent(path, newKey -> new HashMap<String,String>());
  		scoped.put(key, value);
  		return this;
  	}