docs: ServiceName serviceName(final ModelNode operation) {
          String name = null;
          PathAddress pa = PathAddress.pathAddress(operation.require(OP_ADDR));
          for (int i = pa.size() - 1; i > 0; i--) {
              PathElement pe = pa.getElement(i);
              if (key.equals(pe.getKey())) {
                  name = pe.getValue();
                  break;
              }
          }
  
          if (name == null) {
              throw ROOT_LOGGER.operationAddressMissingKey(key);
          }
  
          return serviceName(name);
      }