ColourGradient { static int updateColourValue(int colourValue, int colourDistance) { if (colourDistance < 0) { return colourValue + 1; } else if (colourDistance > 0) { return colourValue - 1; } else { return colourValue; } } protected  ColourGradient(); static String getGradientColour(double value,
                                           double min,
                                           double max,
                                           String lowValueColourString,
                                           String highValueColourString);  }
@Test public void updateColourValue() { assertThat(ColourGradient.updateColourValue(3, 255), is(2)); assertThat(ColourGradient.updateColourValue(3, -255), is(4)); assertThat(ColourGradient.updateColourValue(3, 0), is(3)); }