LinearCost currentChildCost = currentChildRep.getCost();
LinearCost currentChildCost = null; Utils.fail("This part is not implemented in statespace.");
	LinearCost getTotalCost() {	    LinearCost currentCost = LinearCost.ZERO;	    	    Iterator keyIter = this.doReplace.keySet().iterator();	    while(keyIter.hasNext()) {		// the only mappings that we have in the map are the streams we want to include		SIRStream currentStream = (SIRStream)keyIter.next();		LinearFilterRepresentation currentChildRep = linearInformation.getLinearRepresentation(currentStream);		LinearCost currentChildCost = currentChildRep.getCost();		currentCost = currentCost.plus(currentChildCost);	    }	    return currentCost;	}