@Test
	public void testSelfScheduleSnapshot0RemovesScratch() throws Exception {
		try (ToyDBTraceBuilder tb = new ToyDBTraceBuilder("test", "Toy:BE:64:default")) {
			try (Transaction tx = tb.startTransaction()) {
				tb.trace.getTimeManager().getSnapshot(0, true).setSchedule(TraceSchedule.snap(0));
			}

			DBTraceTimeViewport viewport = tb.trace.createTimeViewport();
			viewport.setSnap(10);
			assertEquals(lifeSetOf(Lifespan.span(0, 10)), viewport.spanSet);
		}
	}
Even if the initial snapshot 0 does not exist, we now always truncate at 0 as if it did.
Ghidra/Debug/Framework-TraceModeling/src/test/java/ghidra/trace/database/DBTraceTimeViewportTest.java