Add trailing commas

docs/examples/effects/infinite_effects/lib/main.dart

@@ -6,7 +6,7 @@ import 'package:flutter/material.dart';
 
 import 'package:flame/flame.dart';
 import 'package:flame/game.dart';
-import 'package:infinite_effects/square.dart';
+import './square.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
@@ -37,13 +37,15 @@ class MyGame extends BaseGame with TapDetector {
         speed: 250.0,
         curve: Curves.bounceInOut,
         isInfinite: true,
-        isAlternating: true));
+        isAlternating: true,
+    ));
     redSquare.clearEffects();
     redSquare.addEffect(ScaleEffect(
         size: Size(dx, dy),
         speed: 250.0,
         curve: Curves.easeInCubic,
         isInfinite: true,
-        isAlternating: true));
+        isAlternating: true,
+    ));
   }
 }

docs/examples/effects/infinite_effects/lib/square.dart

@@ -1,3 +1,4 @@
+import 'package:flame/anchor.dart';
 import 'package:flame/components/component.dart';
 
 import 'dart:ui';
@@ -10,6 +11,7 @@ class Square extends PositionComponent {
     height = 100;
     this.x = x;
     this.y = y;
+    anchor = Anchor.center;
   }
 
   @override

lib/effects/move_effect.dart

@@ -22,13 +22,13 @@ class MoveEffect extends PositionComponentEffect {
   double _yDistance;
   double _yDirection;
 
-  MoveEffect(
-      {@required this.destination,
-      @required this.speed,
-      this.curve,
-      isInfinite = false,
-      isAlternating = false})
-      : super(isInfinite, isAlternating);
+  MoveEffect({
+    @required this.destination,
+    @required this.speed,
+    this.curve,
+    isInfinite = false,
+    isAlternating = false,
+  }) : super(isInfinite, isAlternating);
 
   @override
   set component(_comp) {

lib/effects/scale_effect.dart

@@ -19,13 +19,13 @@ class ScaleEffect extends PositionComponentEffect {
   Size _diff;
   final Position _dir = Position.empty();
 
-  ScaleEffect(
-      {@required this.size,
-      @required this.speed,
-      this.curve,
-      isInfinite = false,
-      isAlternating = false})
-      : super(isInfinite, isAlternating);
+  ScaleEffect({
+    @required this.size,
+    @required this.speed,
+    this.curve,
+    isInfinite = false,
+    isAlternating = false,
+  }) : super(isInfinite, isAlternating);
 
   @override
   set component(_comp) {