public void cytronSsa() throws IOException {
IRBody block = parseCytron();
ControlFlowGraph cfg = new ControlFlowGraph(block);
Iterable<BasicBlock> assignmentsToK = Iterables.filter(cfg.getBasicBlocks(),
CfgPredicates.containsAssignmentTo(new EnvironmentVariable("K")));
assertThat(Iterables.size(assignmentsToK), equalTo(3));
DominanceTree dtree = new DominanceTree(cfg);