### Question:
DoubleArrayValueFormatter implements ValueFormatter<double[]> { @Override public String formatForDisplay(double[] array) { return Arrays.toString(array); } private  DoubleArrayValueFormatter(); @Override String formatForCsv(double[] array); @Override String formatForDisplay(double[] array);  }### Answer:
@Test public void formatForDisplay() { double[] array = {1, 2, 3}; assertThat(DoubleArrayValueFormatter.INSTANCE.formatForDisplay(array)).isEqualTo("[1.0, 2.0, 3.0]"); }