anchor.diff:    final List<NamedType> namedParameters; // Must be sorted.
   
     /// The [Typedef] this function type is created for.
  -  TypedefType typedefType;
  +  final TypedefType typedefType;
   
     final DartType returnType;
     int _hashCode;
  
positive.code:     return new FunctionType(positionalParameters, returnType,
          requiredParameterCount: requiredParameterCount,
          namedParameters: namedParameters,
          typedefReference: typedefReference);
    }
  
    /// Looks up the type of the named parameter with the given name.
  
negative.code:       {this.namedParameters: const <NamedType>[],
        this.typeParameters: const <TypeParameter>[],
        int requiredParameterCount,
        this.typedefType})
        : this.positionalParameters = positionalParameters,
          this.requiredParameterCount =
              requiredParameterCount ?? positionalParameters.length;
  
    @nocoq
    Reference get typedefReference => typedefType?.typedefReference;
  
    Typedef get typedef => typedefReference?.asTypedef;
  
  