Basically, I wrote a new class called playlistPanel 

I go to my GUI builder and try to drag the playlistPanel from the view that has all my source files in the Source Packages dir, and then inside <default package>.  I grab playlistPanel.java from the list and attempt to drag it over into my GUI Builder design tab of my DeskTopGUI.java class.  This is the GUI builder I think. and then NetBeans UI freezes.  My task manager says it is running and using approx 55% of my CPU but the UI becomes completely unresponsive and I need a custom JPanel for my senior project :( please help me!
here is my code for my custom JPanel class. 

I also attempted to add my own custom constructor with no parameters and then I have right clicked and added it to my Palette and it still doesn't work!!
I don't know why! I have tried restarting my computer and everything.  Still no luck.

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public class playlistPanel extends JPanel{

private void doDrawing(Graphics g){
            Graphics2D g2d = (Graphics2D)g;
            //get height of panel
            int height = getHeight();
            //get width of panel
            int width = getWidth();
            for(int i = 0; i < height; i+= height/120){
                g2d.drawLine(0, i, width, i);
            }
    }
    
    @Override
    public void paintComponent(Graphics g){
        super.paintComponent(g);
        doDrawing(g);
    }

}
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