Set<SubtreeSpecification> colC = new HashSet<SubtreeSpecification>();
colC.add( subtreeSpecB );
colC.add( subtreeSpecC );
colC.add( subtreeSpecD );
subtreeA = new Subtree( colA );
subtreeACopy = new Subtree( colA );
subtreeB = new Subtree( colB );
subtreeC = new Subtree( colC );
}