Update dart format

@@ -28,7 +28,7 @@ class CartesianGrid extends ChartGrid {
   CartesianGrid({
     required GridAxis xAxis,
     required GridAxis yAxis,
-  })  : _xAxis = xAxis..direction = Axis.horizontal,
+  })   : _xAxis = xAxis..direction = Axis.horizontal,
         _yAxis = yAxis..direction = Axis.vertical;
 
   final GridAxis _xAxis;

@@ -608,7 +608,7 @@ class ListView extends StatelessWidget {
     this.padding,
     required this.itemBuilder,
     required this.itemCount,
-  })  : children = null,
+  })   : children = null,
         separatorBuilder = null,
         super();
 
@@ -619,7 +619,7 @@ class ListView extends StatelessWidget {
     required this.itemBuilder,
     required this.separatorBuilder,
     required this.itemCount,
-  })  : children = null,
+  })   : children = null,
         spacing = null,
         super();
 

@@ -106,7 +106,7 @@ class FlatButton extends SingleChildWidget {
     this.flags,
     required Widget child,
     required this.name,
-  })  : _childDown = Container(
+  })   : _childDown = Container(
           child: DefaultTextStyle(
             style: TextStyle(color: textColor),
             child: child,

@@ -46,7 +46,7 @@ class Context {
     PdfPage? page,
     PdfGraphics? canvas,
     required HashMap<Type, Inherited> inherited,
-  })  : _page = page,
+  })   : _page = page,
         _canvas = canvas,
         _inherited = inherited;