@Test
public void testGetAverage() {

	assertEquals(Double.NaN, list1.getAverage());
	list1.addValue(-1L, 10F);
	list1.addValue(-2L, -3F);
	list1.addValue(30L, 3F);
	list1.addValue(2L, -100F);
	list1.addValue(31L, -102F);
	/* expected = Sum([ 10, 3, -100]) = -89/3 ~ -29.67 */
	assertEquals(-29.67, list1.getAverage());
}