run dart fix --apply

Author: hellohuanlin

packages/diagrams/lib/src/basic_shapes.dart

@@ -167,8 +167,8 @@ class LineDiagramPainter extends CustomPainter {
       ..style = PaintingStyle.stroke
       ..color = _kForegroundColor;
 
-    final Offset start = const Offset(2, 4) * _kGridSize;
-    final Offset end = const Offset(8, 2) * _kGridSize;
+    const Offset start = Offset(2, 4) * _kGridSize;
+    const Offset end = Offset(8, 2) * _kGridSize;
 
     canvas.drawLine(
       start,
@@ -590,7 +590,7 @@ class CircleDiagramPainter extends CustomPainter {
 
     final Paint paint = Paint();
 
-    final Offset center = const Offset(6.5, 4) * _kGridSize;
+    const Offset center = Offset(6.5, 4) * _kGridSize;
     final Rect rect = Rect.fromCircle(
       center: center,
       radius: 3 * _kGridSize,