src/com/wentch/redkale/util/Sheet.java

@@ -36,14 +36,15 @@ public class Sheet<T> implements java.io.Serializable {
         return data == null ? new Sheet<>() : new Sheet<>(data.size(), data);
     }
 
-    public void copyTo(Sheet<T> copy) {
-        if (copy == null) return;
+    public Sheet<T> copyTo(Sheet<T> copy) {
+        if (copy == null) return copy;
         copy.total = this.total;
         if (this.getRows() != null) {
             copy.setRows(new ArrayList<>(this.getRows()));
         } else {
             copy.rows = null;
         }
+        return copy;
     }
 
     /**