SIRTwoStageFilter twoStage = (SIRTwoStageFilter)str;
return false; /*
    private static boolean isFusable(SIRStream str) {	// don't allow two-stage filters that peek	if (str instanceof SIRTwoStageFilter) {	    SIRTwoStageFilter twoStage = (SIRTwoStageFilter)str;	    if (twoStage.getInitPeek()-twoStage.getInitPop()>0) {		return false;	    }	}	return (str instanceof SIRFilter) && ((SIRFilter)str).needsWork();	}