### Question:
CorrelationId { public CorrelationId(String correlationAsText) { correlation = (Long.parseLong(correlationAsText, 16)); } CorrelationId(String correlationAsText);  CorrelationId(); @Override String toString(); long getUnderlyingId(); @Override boolean equals(Object o); @Override int hashCode(); final static CorrelationId EMPTY_CORRELATION; }### Answer:
@Test void testCorrelationId() { CorrelationId id = new CorrelationId(); CorrelationId id2 = new CorrelationId(); assertNotEquals(id, id2); CorrelationId idCopy = new CorrelationId(id.toString()); assertEquals(id, idCopy); }