如何使用Pyqt5显示重叠的QWidgets？

from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QLabel, QPushButton, QStackedWidget
import sys

class Page1(QWidget):
    def __init__(self):
        super().__init__()
        layout = QVBoxLayout()
        label = QLabel("Page 1")
        layout.addWidget(label)
        self.setLayout(layout)

class Page2(QWidget):
    def __init__(self):
        super().__init__()
        layout = QVBoxLayout()
        label = QLabel("Page 2")
        layout.addWidget(label)
        self.setLayout(layout)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    stackedWidget = QStackedWidget()
    page1 = Page1()
    page2 = Page2()
    stackedWidget.addWidget(page1)
    stackedWidget.addWidget(page2)
    stackedWidget.setCurrentIndex(0)
    stackedWidget.show()
    sys.exit(app.exec_())

from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QLabel, QPushButton, QTabWidget
import sys

class Page1(QWidget):
    def __init__(self):
        super().__init__()
        layout = QVBoxLayout()
        label = QLabel("Page 1")
        layout.addWidget(label)
        self.setLayout(layout)

class Page2(QWidget):
    def __init__(self):
        super().__init__()
        layout = QVBoxLayout()
        label = QLabel("Page 2")
        layout.addWidget(label)
        self.setLayout(layout)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    tabWidget = QTabWidget()
    page1 = Page1()
    page2 = Page2()
    tabWidget.addTab(page1, "Page 1")
    tabWidget.addTab(page2, "Page 2")
    tabWidget.setCurrentIndex(0)
    tabWidget.show()
    sys.exit(app.exec_())