### Question:
Measurement { @Override public String toString() { return "Measurement(" + id.toString() + "," + timestamp + "," + value + ")"; } Measurement(Id id, long timestamp, double value); Id id(); long timestamp(); double value(); @Override boolean equals(Object obj); @Override int hashCode(); @Override String toString();  }### Answer:
@Test public void testToString() { Id id = new DefaultId("foo"); Measurement m = new Measurement(id, 42L, 42.0); Assertions.assertEquals(m.toString(), "Measurement(foo,42,42.0)"); }