System.out.println("jl5 assign: left is: "+left.getClass());
    public Assign JL5Assign(Position pos, Expr left, Assign.Operator op, Expr right){        System.out.println("jl5 assign: left is: "+left.getClass());        if (left instanceof Local){            return JL5LocalAssign(pos, left, op, right);        }        else if (left instanceof Field){            return JL5FieldAssign(pos, left, op, right);        }        else if (left instanceof ArrayAccess){            return JL5ArrayAccessAssign(pos, left, op, right);        }        else {            return JL5AmbAssign(pos, left, op, right);        }    }