code: private Map<String, String> toConfigurationItemMap(Set<ConfigurationItem> configurationItems) {
          Map<String, String> map = new HashMap<>(configurationItems.size());
  
          for (ConfigurationItem configurationItem : configurationItems) {
              map.put(configurationItem.getKey(), configurationItem.getValue());
          }
  
          return map;
      }
docs: Converts a {@code Set} of {@code ConfigurationItem}s to a {@code Map} of {@code String} and {@code String}.
  
  @param configurationItems a {@code Set} of {@code ConfigurationItem}s.
  @return a {@code Map} of {@code String} and {@code String}.