@Test
 public void testWrongValueSum() {
   SumOperation op = new SumOperation("foo");
   Metric metric = new Metric();
   metric.getValues().put("bar", 1.0);
   op.process(metric);
   op.process(metric);
   op.process(metric);
   assertEquals((double) 0.0, op.getResult(), 0.1);
 }
 @Test
 public void testSumAgain() {
   SumOperation op = new SumOperation("foo");
   Metric metric = new Metric();
   metric.getValues().put("foo", 5.3);
   op.process(metric);
   metric.getValues().clear();
   metric.getValues().put("foo", 4.7);
   op.process(metric);
   assertEquals((double) 10.0, op.getResult(), 0.001);
 }