public void createNodes(FlatNode top, HashMap[] exeCounts) {
inputNodes = new HashMap<SIROperator, InputSliceNode>();
outputNodes = new HashMap<SIROperator, OutputSliceNode>();
filterNodes = new HashMap<SIROperator, FilterSliceNode>();
generatedIds = new HashSet<FilterSliceNode>();
this.exeCounts = exeCounts;
top.accept(this, null, true);
}