private void waitForPreviousTestToFinish() {
		if (lastTestThread == null) {
			return;
		}

		long reasonableTimeoutMillis = 15000;
		try {
			lastTestThread.join(reasonableTimeoutMillis);
		}
		catch (InterruptedException e) {
			// we tried our best; just continue on
		}
	}
Prints all exceptions found that did not occur on the test thread.  This is useful 
for debugging.
Ghidra/Framework/Generic/src/main/java/generic/test/ConcurrentTestExceptionStatement.java