我計劃從基礎開發一個方程求解器，并能夠使用以下代碼進行基本的數學運算。我使用了一個令牌堆棧結構，用于存儲分隔符和數字令牌。雖然這個實現太基礎了，但我想在以后的版本中改進它。我只需要一些幫助我使用數據結構將令牌存儲為一組堆棧的方式。請提出任何錯誤？import java.util.ArrayList;import java.util.Stack;class TokenStack<N, D> {    private Stack<N> numberStack;    private Stack<D> delimStack;    public TokenStack() {        numberStack = new Stack<N>();        delimStack = new Stack<D>();    }    public void pushN(N num) {        numberStack.push(num);    }    public N popN() {        return numberStack.pop();    }    public void pushD(D delim) {        delimStack.push(delim);    }    public D popD() {        return delimStack.pop();    }    public boolean isEmptyN() {        return numberStack.isEmpty();    }    public boolean isEmptyD() {        return delimStack.isEmpty();    }}public class GeneralST {    private static final char SPACE_DELIM = ' ';    private static final char ADD_DELIM = '+';    private static final char SUB_DELIM = '-';    private static final char MUL_DELIM = '*';    private static final char DIV_DELIM = '/';    protected static final char EQU_DELIM = '=';    private TokenStack<String, Character> tokens = new TokenStack<String, Character>();    protected ArrayList<Character> acceptedDelims = new ArrayList<Character>();    protected ArrayList<Character> mathsDelims = new ArrayList<Character>();    protected double result;    public double getResult() {        return result;    }    protected void setupDelims() {        acceptedDelims.add(SPACE_DELIM);        mathsDelims.add(ADD_DELIM);        mathsDelims.add(SUB_DELIM);        mathsDelims.add(MUL_DELIM);        mathsDelims.add(DIV_DELIM);        acceptedDelims.addAll(mathsDelims);    }