don't import *

src/view/NodeView.java

@@ -8,7 +8,8 @@ import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Point;
 
-import javax.swing.*;
+import javax.swing.BorderFactory;
+import javax.swing.JPanel;
 import javax.swing.border.Border;
 
 import bk.ExtremalLayoutCalc.LayoutType;