### Question:
SVGAttributeParser { public static String rgbToHexString(final int r, final int g, final int b) { return rgbToHexString(r, g, b, 1); }  static double toPixelValue(final String value,
                                      final double defaultValue); static double toPixelValue(final String value); static String toHexColorString(final String raw); static String rgbToHexString(final int r, final int g, final int b); static String rgbToHexString(final int r, final int g, final int b, final int a); static String rgbToHexString(int rgb); static int toRGB(final int r,
                            final int g,
                            final int b,
                            final int a);  }### Answer:
@Test public void testRGBToHexString() { assertEquals("#000000", SVGAttributeParser.rgbToHexString(0, 0, 0, 1)); assertEquals("#0000ff", SVGAttributeParser.rgbToHexString(0, 0, 255, 1)); assertEquals("#ff0000", SVGAttributeParser.rgbToHexString(255, 0, 0, 1)); assertEquals("#ffffff", SVGAttributeParser.rgbToHexString(255, 255, 255, 1)); }