学习PySide6时犯了一个低级错误（窗口居中问题）

在学习PySide6时，犯了一个低级错误，我写了一段代码

import sys

from PySide6.QtCore import Qt
from PySide6.QtWidgets import (QApplication, QCheckBox, QDialog,
                               QDialogButtonBox, QGridLayout, QHBoxLayout,
                               QLabel, QLayout, QLineEdit, QPushButton,
                               QVBoxLayout, QWidget)


class Window(QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)

        label = QLabel("Find &what:")
        line_edit = QLineEdit()
        label.setBuddy(line_edit)

        case_check_box = QCheckBox("Match &case")
        from_start_check_box = QCheckBox("Search from &start")
        from_start_check_box.setChecked(True)

        find_button = QPushButton("&Find")
        find_button.setDefault(True)

        button_box = QDialogButtonBox(Qt.Vertical)
        b