drag from script editor to shelf in maya 2020

mimedata_maya_drag_scripteditor_to_shelf.py

from PySide2 import QtWidgets, QtGui, QtCore

class Window(QtWidgets.QWidget):
    def __init__(self, *args):
        QtWidgets.QWidget.__init__(self, *args)
        layout = QtWidgets.QVBoxLayout(self)
        label= QtWidgets.QLabel('drop here')
        label.setAlignment(QtCore.Qt.AlignCenter)
        layout.addWidget(label)
        self.setLayout(layout)
        self.setAcceptDrops(True)

    def dropEvent(self, event):
        data = event.mimeData()
        print('formats:', data.formats())
        encoded = data.data('application/x-maya-data')
        stream = QtCore.QDataStream(encoded, QtCore.QIODevice.ReadOnly)
        # can not figure out what the structure is in stream though
        event.acceptProposedAction()

    def dragEnterEvent(self, e):
        e.accept()

win = Window()
win.show()