### Question:
PanLine extends JPanel { public String getThickness() { return textFieldSize.getText().trim(); } 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 testGetThickness() { JTextField textField = new JTextField(); textField.setText("5 "); Whitebox.setInternalState(panLine, "textFieldSize", textField); String actual = panLine.getThickness(); String expected = "5"; assertEquals(expected, actual); }