How to use the photini.pyqt.QtGui.QPixmap function in Photini

def load_thumbnail(self):
        pixmap = QtGui.QPixmap()
        thumb = self.metadata.thumbnail
        if thumb:
            pixmap.loadFromData(thumb.data)
        if pixmap.isNull():
            self.image.setText(translate('ImageList', 'No\nthumbnail\nin file'))
            return
        pixmap = self.transform(pixmap, self.metadata.orientation)
        self.image.setPixmap(
            pixmap.scaled(self.thumb_size, self.thumb_size,
                          Qt.KeepAspectRatio, Qt.SmoothTransformation))

candidates.append(candidate)
        if not candidates:
            return None
        rsp = requests.get(photo['url_t'])
        if rsp.status_code == 200:
            flickr_icon = rsp.content
        else:
            logger.error('HTTP error %d (%s)', rsp.status_code, photo['url_t'])
            return None
        # get user to choose matching image file
        dialog = QtWidgets.QDialog(parent=self)
        dialog.setWindowTitle(translate('FlickrTab', 'Select an image'))
        dialog.setLayout(QtWidgets.QFormLayout())
        dialog.layout().setFieldGrowthPolicy(
            QtWidgets.QFormLayout.AllNonFixedFieldsGrow)
        pixmap = QtGui.QPixmap()
        pixmap.loadFromData(flickr_icon)
        label = QtWidgets.QLabel()
        label.setPixmap(pixmap)
        dialog.layout().addRow(label, QtWidgets.QLabel(translate(
            'FlickrTab', 'Which image file matches\nthis picture on Flickr?')))
        divider = QtWidgets.QFrame()
        divider.setFrameStyle(QtWidgets.QFrame.HLine)
        dialog.layout().addRow(divider)
        buttons = {}
        for candidate in candidates:
            label = QtWidgets.QLabel()
            pixmap = candidate.image.pixmap()
            if pixmap:
                label.setPixmap(pixmap)
            else:
                label.setText(candidate.image.text())

def __init__(self, options, initial_files):
        super(MainWindow, self).__init__()
        self.setWindowTitle(translate(
            'MenuBar', "Photini photo metadata editor"))
        pixmap = QtGui.QPixmap()
        pixmap.loadFromData(pkg_resources.resource_string(
            'photini', 'data/icons/48/photini.png'))
        icon = QtGui.QIcon(pixmap)
        self.setWindowIcon(icon)
        self.selection = list()
        # logger window
        self.loggerwindow = LoggerWindow(options.verbose)
        self.loggerwindow.setWindowIcon(icon)
        # set network proxy
        proxies = getproxies()
        if 'http' in proxies:
            parsed = urlparse(proxies['http'])
            QNetworkProxy.setApplicationProxy(QNetworkProxy(
                QNetworkProxy.HttpProxy, parsed.hostname, parsed.port))
        # create shared global objects
        self.app = QtWidgets.QApplication.instance()

def write(self, handler, tag):
        if handler.is_xmp_tag(tag):
            data = self.data
            if self.fmt != 'JPEG':
                pixmap = QtGui.QPixmap()
                pixmap.loadFromData(data)
                buf = QtCore.QBuffer()
                buf.open(QtCore.QIODevice.WriteOnly)
                pixmap.save(buf, 'JPEG')
                data = buf.data().data()
                w = pixmap.width()
                h = pixmap.height()
            else:
                w, h = self.size()
            data = codecs.encode(data, 'base64_codec')
            if not six.PY2:
                data = data.decode('ascii')
            handler.set_string(tag, (data, 'JPEG', str(w), str(h)))
        elif handler.is_exif_tag(tag):
            handler.set_exif_thumbnail_from_buffer(self.data)