assigned.add(node);
layout.assigned.add(node);
    public void visitNode(FlatNode node)     {	if (node.contents instanceof SIRFilter &&	    ! (FileVisitor.fileNodes.contains(node))) {	    //do not map identities, but add them to the identities set	    if (node.contents instanceof SIRIdentity) {		identities.add(node);		return;	    }	    assigned.add(node);	    return;	}	if (node.contents instanceof SIRJoiner) {	    if (node.edges[0] == null || !(node.edges[0].contents instanceof SIRJoiner)) {		//do not assign the joiner if JoinerRemoval wants is removed...		if (JoinerRemoval.unnecessary != null && 		    JoinerRemoval.unnecessary.contains(node))		    return;		//do not assign the joiner if it is a null joiner		for (int i = 0; i < node.inputs;i++) {		    if (node.incomingWeights[i] != 0) {			joiners.add(node);			assigned.add(node);			return;		    }		} 	    }	}    }