code: private Map<ConfigurationKey, Object> getSystemProperties() {
          Map<ConfigurationKey, Object> found = new EnumMap<ConfigurationKey, Object>(ConfigurationKey.class);
          for (ConfigurationKey key : ConfigurationKey.values()) {
              String property = getSystemProperty(key.get());
              if (property != null) {
                  processKeyValue(found, key, property);
              }
          }
          return found;
      }
docs: Iterate through the {@link ConfigurationKey#values()} and try to get a system property for every key. The value is automatically converted - a runtime
  exception may be thrown during conversion.
  
  @return all the properties set as system properties