@Test (expected = IllegalStateException.class)
    public void assertReuseRemovedNode() {
        populateSpanTree();
        root.remove(span3);
        tree.annotate(span3, new Annotation(at1));
    }
@author <a href="mailto:mpraveen@yahoo-inc.com">Praveen Mohan</a>

This test covers all possible scenarios in SpanTree.
document/src/test/java/com/yahoo/document/annotation/SpanTreeAdvTest.java