@After
    public void removeTree() {
        tree = null;
    }
@author <a href="mailto:mpraveen@yahoo-inc.com">Praveen Mohan</a>

This test checks if sub-trees are sorted appropriately by probability
within an alternate span list and getFrom() and getTo() are updated properly
when the trees are sorted.
document/src/test/java/com/yahoo/document/annotation/Bug4164299TestCase.java