### Question:
MinTimestampTracker implements TimestampTracker<E> { public long get() { Stamped<E> stamped = ascendingSubsequence.peekFirst(); if (stamped == null) return lastKnownTime; else return stamped.timestamp; }  void addElement(final Stamped<E> elem); void removeElement(final Stamped<E> elem); int size(); long get();  }### Answer:
@Test public void shouldReturnNotKnownTimestampWhenNoRecordsEverAdded() throws Exception { assertThat(tracker.get(), equalTo(TimestampTracker.NOT_KNOWN)); }