BoxLayout can't be shared - Qual o erro da classe abaixo?

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buttonPanel3.setLayout(new BoxLayout(buttonPanel3,BoxLayout.X_AXIS));
		buttonPanel4.setLayout(new BoxLayout(buttonPanel2,BoxLayout.Y_AXIS));
		
		buttonPanel1.add(log);//use BoxLayout
		buttonPanel1.add(ta1);
		buttonPanel2.add(label1); 		
		buttonPanel2.add(openButton);//use BoxLayout
		buttonPanel3.add(ta2);
		buttonPanel4.add(label2);
		buttonPanel4.add(generateButton);
		
		//Create a file chooser
        fc = new JFileChooser();

        //Add the button panels
        add(buttonPanel1);
        add(buttonPanel2);

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