PySide2如何将分离的图例放置到另一个小部件？

import sys
from PySide2.QtWidgets import QApplication, QMainWindow, QVBoxLayout, QWidget
from PySide2.QtCharts import QtCharts

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        # 创建图表和图例对象
        chart = QtCharts.QChart()
        legend = QtCharts.QLegend()

        # 创建需要显示图例的图表或绘图小部件
        series = QtCharts.QLineSeries()
        series.append(0, 6)
        series.append(2, 4)
        series.append(3, 8)
        series.append(7, 4)
        chart.addSeries(series)

        # 将图例对象与图表关联
        chart.setLegend(legend)

        # 创建一个小部件，并将图例对象添加到布局中
        widget = QWidget()
        layout = QVBoxLayout()
        layout.addWidget(chart)
        layout.addWidget(legend)
        widget.setLayout(layout)

        self.setCentralWidget(widget)

if __name__ == "__main__":
    app = QApplication(sys.argv)
    mainWindow = MainWindow()
    mainWindow.show()
    sys.exit(app.exec_())