diff --git a/lib/src/main/java/com/vrg/flipview/DoubleFlipView.java b/lib/src/main/java/com/vrg/flipview/DoubleFlipView.java
index 4d32826..f1bac5d 100644
--- a/lib/src/main/java/com/vrg/flipview/DoubleFlipView.java
+++ b/lib/src/main/java/com/vrg/flipview/DoubleFlipView.java
@@ -271,3 +271,4 @@ public interface OnItemClickListener<I>{
     }
 }
 
+
diff --git a/lib/src/main/java/com/vrg/flipview/FlipView.java b/lib/src/main/java/com/vrg/flipview/FlipView.java
index dccd76b..3a1791d 100644
--- a/lib/src/main/java/com/vrg/flipview/FlipView.java
+++ b/lib/src/main/java/com/vrg/flipview/FlipView.java
@@ -241,3 +241,4 @@ public interface ViewBinder<I> {
     }
 }
 
+
diff --git a/sample/src/main/java/com/vrg/sample/ImageBinder.java b/sample/src/main/java/com/vrg/sample/ImageBinder.java
index d6a2d8a..8d9cd23 100644
--- a/sample/src/main/java/com/vrg/sample/ImageBinder.java
+++ b/sample/src/main/java/com/vrg/sample/ImageBinder.java
@@ -34,3 +34,4 @@ public int getBackSideLayoutRes() {
         return R.layout.item_back;
     }
 }
+
diff --git a/sample/src/main/java/com/vrg/sample/MainActivity.java b/sample/src/main/java/com/vrg/sample/MainActivity.java
index 60d6530..3632696 100644
--- a/sample/src/main/java/com/vrg/sample/MainActivity.java
+++ b/sample/src/main/java/com/vrg/sample/MainActivity.java
@@ -49,3 +49,4 @@ public void onItemClick(int position, boolean left, ImageItem item) {
         container.notifyDatasetChanged();
     }
 }
+