anchor.diff:      }
     }
   
  +  // Emit call to a specific method.
  +  void emitCall(int depth, String name, List<DartType> proto) {
  +    emit(name);
  +    emitExprList(depth + 1, proto);
  +  }
  +
     // Helper for a method call.
     bool pickedCall(
         int depth, DartType tp, String name, List<List<DartType>> protos, int m) {
       for (int i = m - 1; i >= 0; i--) {
         if (tp == protos[i][0]) {
  -        emit('$name$i');
  -        emitExprList(depth + 1, protos[i]);
  +        emitCall(depth + 1, "$name$i", protos[i]);
           return true;
         }
       }
  
positive.code:         if (tp == proto[i]) choices.add('$paramName$i');
        }
      }
      // Remove possible modification of the iteration variable from the loop
      // body.
      if (isLhs) {
        if (rand.nextInt(10) != 0) {
          Set<String> cleanChoices = choices.difference(Set.from(iterVars));
          if (cleanChoices.isNotEmpty) {
            choices = cleanChoices;
  
negative.code: // Version of DartFuzz. Increase this each time changes are made
  // to preserve the property that a given version of DartFuzz yields
  // the same fuzzed program for a deterministic random seed.
  const String version = '1.31';
  
  // Restriction on statements and expressions.
  const int stmtLength = 2;
  