/** Method for constructing a new instance that is configured with specified features enabled. */
 public ObjectWriter without(SerializationFeature first, SerializationFeature... other) {
   SerializationConfig newConfig = _config.without(first, other);
   return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
 }
 /** Method for constructing a new instance that is configured with specified feature enabled. */
 public ObjectWriter without(SerializationFeature feature) {
   SerializationConfig newConfig = _config.without(feature);
   return (newConfig == _config) ? this : new ObjectWriter(this, newConfig);
 }