private void initialize(Map<String, String> options) {
    if (drawer == null) {
      drawer = new CFGToDotGraph();
      drawer.setBriefLabels(PhaseOptions.getBoolean(options, briefLabelOptionName));
      drawer.setOnePage(!PhaseOptions.getBoolean(options, multipageOptionName));
      drawer.setUnexceptionalControlFlowAttr("color", "black");
      drawer.setExceptionalControlFlowAttr("color", "red");
      drawer.setExceptionEdgeAttr("color", "lightgray");
      drawer.setShowExceptions(Options.v().show_exception_dests());
      ir = CFGIntermediateRep.getIR(PhaseOptions.getString(options, irOptionName));
      graphtype = CFGGraphType.getGraphType(PhaseOptions.getString(options, graphTypeOptionName));

      AltClassLoader.v().setAltClassPath(PhaseOptions.getString(options, altClassPathOptionName));
      AltClassLoader.v()
          .setAltClasses(
              new String[] {
                "soot.toolkits.graph.ArrayRefBlockGraph",
                "soot.toolkits.graph.Block",
                "soot.toolkits.graph.Block$AllMapTo",
                "soot.toolkits.graph.BlockGraph",
                "soot.toolkits.graph.BriefBlockGraph",
                "soot.toolkits.graph.BriefUnitGraph",
                "soot.toolkits.graph.CompleteBlockGraph",
                "soot.toolkits.graph.CompleteUnitGraph",
                "soot.toolkits.graph.TrapUnitGraph",
                "soot.toolkits.graph.UnitGraph",
                "soot.toolkits.graph.ZonedBlockGraph",
              });
    }
  }
  /**
   * Traverse the statements in the given body, looking for aggregation possibilities; that is,
   * given a def d and a use u, d has no other uses, u has no other defs, collapse d and u.
   *
   * <p>option: only-stack-locals; if this is true, only aggregate variables starting with $
   */
  protected void internalTransform(Body b, String phaseName, Map<String, String> options) {
    StmtBody body = (StmtBody) b;
    boolean onlyStackVars = PhaseOptions.getBoolean(options, "only-stack-locals");

    int aggregateCount = 1;

    if (Options.v().time()) Timers.v().aggregationTimer.start();
    boolean changed = false;

    Map<ValueBox, Zone> boxToZone =
        new HashMap<ValueBox, Zone>(body.getUnits().size() * 2 + 1, 0.7f);

    // Determine the zone of every box
    {
      Zonation zonation = new Zonation(body);

      for (Unit u : body.getUnits()) {
        Zone zone = zonation.getZoneOf(u);

        for (ValueBox box : u.getUseBoxes()) {
          boxToZone.put(box, zone);
        }

        for (ValueBox box : u.getDefBoxes()) {
          boxToZone.put(box, zone);
        }
      }
    }

    do {
      if (Options.v().verbose())
        G.v()
            .out
            .println(
                "["
                    + body.getMethod().getName()
                    + "] Aggregating iteration "
                    + aggregateCount
                    + "...");

      // body.printTo(new java.io.PrintWriter(G.v().out, true));

      changed = internalAggregate(body, boxToZone, onlyStackVars);

      aggregateCount++;
    } while (changed);

    if (Options.v().time()) Timers.v().aggregationTimer.end();
  }