docs: @Override
      public ProtocolDefaults getValue() {
          ProtocolStackConfigurator configurator = load(ProtocolDefaultsBuilder.this.resource);
          for (org.jgroups.conf.ProtocolConfiguration config: configurator.getProtocolStack()) {
              this.map.put(config.getProtocolName(), Collections.unmodifiableMap(config.getProperties()));
          }
          return this;
      }