icon size not change

[azamcsc]

i try to change icon size by put size in itemBuilder..but nothing happen

[azamcsc]

updated : using itemSize in ratingbar
RatingBar(
initialRating: double.parse(tutor_rating),
direction: Axis.horizontal,
allowHalfRating: true,
itemCount: 5,
itemSize: 15,
itemPadding: EdgeInsets.symmetric(horizontal: 4.0),
itemBuilder: (context, _) => Icon(
Icons.star,
color: Colors.amber,
),
onRatingUpdate: (rating) {
print(rating);
},
),