How to use the reprounzip-qt.reprounzip_qt.gui.unpack.UnpackTab function in reprounzip-qt

def __init__(self, package='', **kwargs):
        super(UnpackTab, self).__init__(**kwargs)

        layout = QtGui.QGridLayout()
        layout.addWidget(QtGui.QLabel("RPZ package:"), 0, 0)
        self.package_widget = QtGui.QLineEdit(package, enabled=False)
        layout.addWidget(self.package_widget, 0, 1)
        browse_pkg = QtGui.QPushButton("Browse")
        browse_pkg.clicked.connect(self._browse_pkg)
        layout.addWidget(browse_pkg, 0, 2)

        layout.addWidget(QtGui.QLabel("Unpacker:"), 1, 0,
                         QtCore.Qt.AlignTop)
        ulayout = QtGui.QVBoxLayout()
        self.unpackers = QtGui.QButtonGroup()
        for i, name in enumerate(n for n, c in self.UNPACKERS):
            radio = QtGui.QRadioButton(name)
            self.unpackers.addButton(radio, i)