anchor.diff:  class NominalType extends AbstractType {
     
     ClassElement element;
  -  ConstraintAnalysis constraintAnalysis;
  -    
  -  
  -  NominalType(ClassElement this.element, ConstraintAnalysis this.constraintAnalysis);
  +    
  +  
  +  NominalType(ClassElement this.element);
    
     
     String toString() => element.name.toString();
  
positive.code:   visitIntegerLiteral(IntegerLiteral n) {
      super.visitIntegerLiteral(n);
      // {double} \subseteq [n]
      types.put(n, new NominalType(elementAnalysis.resolveClassElement("int", constraintAnalysis.dartCore, source), this.constraintAnalysis));
    }
    
    visitDoubleLiteral(DoubleLiteral n) {
      super.visitDoubleLiteral(n);
      // {double} \subseteq [n]
      types.put(n, new NominalType(elementAnalysis.resolveClassElement("double", constraintAnalysis.dartCore, source), this.constraintAnalysis));
    }
    
    visitVariableDeclaration(VariableDeclaration vd){
  
negative.code:   
    ExpressionTypeIdentifier(Expression this.exp);
    
    int get hashCode => exp.hashCode;
  }
  
  
  