@Before
    public void buildTree() {
        SpanList root = new SpanList();
        AlternateSpanList branch = new AlternateSpanList();
        tree = new SpanTree("test", root);

        SpanNode span1 = new Span(0, 2);
        SpanNode span2 = new Span(2, 2);
        SpanNode span3 = new Span(4, 2);

        SpanNode span11 = new Span(10, 2);
        SpanNode span22 = new Span(12, 2);
        SpanNode span33 = new Span(14, 2);

        branch.add(span3);
        branch.add(span2);
        branch.add(span1);

        List<SpanNode> subtreeList = new ArrayList<SpanNode>();
        subtreeList.add(span11);
        subtreeList.add(span22);
        subtreeList.add(span33);
        branch.addChildren(1, subtreeList, 50.0d);
        root.add(branch);

    }
@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