System.out.println("peek(): " + variable);
	public Variable peek() {		System.out.println("peek(): " + variable);		int n = stack.size();		// TODO don't know if this right, but it avoids exceptions for certain		// rewritePhiParams calls		if (n <= 0) {			return null;		}		Variable var = (Variable) stack.get(n - 1);		System.out.println("peek(): " + var);		return var;	}