anchor.diff:      this.declared,
       this.implemented,
       this._noSuchMethodForwarders,
  -    this._implementedForMixing,
       this._overridden,
       this._superImplemented,
       this.conflicts,
  
positive.code: 
    /// The set of names that are `noSuchMethod` forwarders in [implemented].
    final Set<Name> _noSuchMethodForwarders;
  
    /// The map of names to their concrete implementations that can be mixed
    /// when this type is used as a mixin.
    final Map<Name, ExecutableElement> _implementedForMixing;
  
    /// The map of names to their signatures from the mixins, superclasses,
    /// or interfaces.
  
negative.code:       declared,
        implemented,
        noSuchMethodForwarders,
        namedCandidates,
        superImplemented,
        conflicts ?? const [],
  