anchor.diff:      Iterable product([Iterable other]) => Iterable.$product(this, other);
       Iterable get cycled => Iterable.$get$cycled(this);
       Iterable interpose([$dart$core.Object element, $dart$core.Object step = $package$dart$default]) => Iterable.$interpose(this, element, step);
  +    Iterable get distinct => Iterable.$get$distinct(this);
  +    Map group([Callable grouping]) => Iterable.$group(this, grouping);
       $dart$core.bool containsEvery([Iterable elements]) => Category.$containsEvery(this, elements);
       $dart$core.bool containsAny([Iterable elements]) => Category.$containsAny(this, elements);
   }
  
positive.code:     $dart$core.bool contains([$dart$core.Object element]) => Empty.$contains(this, element);
      $dart$core.bool defines([Integer index]) => Empty.$defines(this, index);
      Empty get keys => Empty.$get$keys(this);
      $dart$core.bool get empty => Empty.$get$empty(this);
      $dart$core.int get size => Empty.$get$size(this);
      Empty get reversed => Empty.$get$reversed(this);
  
negative.code:     Sequential prepend([Sequential elements]);
      $dart$core.String toString();
      static $dart$core.String $get$string([final Sequential $this]) => (($dart$core.String $lhs$) => $lhs$ == null ? ("[" + $package$commaList($this)) + "]" : $lhs$)($this.empty ? "[]" : null);
  }
  serialization$DeserializationContext $package$serialization$deserialization() => new serialization$DeserializationContextImpl();
  
  serialization$DeserializationContext deserialization() => $package$deserialization();
  
  abstract class serialization$DeserializationContext {
      void instance([$dart$core.Object instanceId, meta$model$ClassModel clazz]);
      void memberInstance([$dart$core.Object containerId, $dart$core.Object instanceId]);
      void attribute([$dart$core.Object instanceId, meta$declaration$ValueDeclaration attribute, $dart$core.Object attributeValueId]);
      void element([$dart$core.Object instanceId, $dart$core.int index, $dart$core.Object elementValueId]);
      void instanceValue([$dart$core.Object instanceId, $dart$core.Object instanceValue]);
      $dart$core.Object reconstruct([$dart$core.Object instanceId]);
  }
  abstract class serialization$Element implements serialization$ReachableReference {
      $dart$core.int get index;
  }
  abstract class serialization$Member implements serialization$ReachableReference {
      meta$declaration$ValueDeclaration get attribute;
      $dart$core.Object referred([$dart$core.Object instance]);
  }
  abstract class serialization$Outer implements serialization$ReachableReference {
      $dart$core.Object referred([$dart$core.Object instance]);
  }
  abstract class serialization$ReachableReference {
      $dart$core.Object referred([$dart$core.Object instance]);
  }
  abstract class serialization$References implements Iterable {
      $dart$core.Object get instance;
      Iterable get references;
  }
  serialization$SerializationContext $package$serialization$serialization() => new serialization$SerializationContextImpl();
  
  serialization$SerializationContext serialization() => $package$serialization();
  
  abstract class serialization$SerializationContext {
      serialization$References references([$dart$core.Object instance]);
  }
  abstract class Set implements Collection {
      $dart$core.bool contains([$dart$core.Object element]);
  