### Question:
PanLine extends JPanel { public void setCustomWidth(String width) { textFieldWidth.setText(width); } PanLine(); String getAlign(); String getThickness(); String getCustomWidth(); String getCustomWidthUnit(); String getColor(); void setAlign(EnumAlign enumAlign); void setThickness(String thickness); void setCustomWidth(String width); void setCustomWidthUnit(EnumWidthUnit enumWidthUnit); void setColor(String hexValue);  }### Answer:
@Test public void testSetCustomWidth() { JTextField textField = new JTextField(); textField.setText("5 "); Whitebox.setInternalState(panLine, "textFieldWidth", textField); panLine.setCustomWidth("7"); String expected = "7"; String actual = textField.getText(); assertEquals(expected, actual); }