def load(self, requirements_file=None):
        """Load or reload requirements from a requirements.txt file.

        :param requirements_file: if not given, the filename used from
            initialization will be read again.
        """
        if requirements_file is None:
            requirements_file = self.filename
            if requirements_file is None:
                raise ValueError("no filename provided")
        elif isinstance(requirements_file, text_type):
            requirements_file = Path(requirements_file)
        self.clear()
        with requirements_file.open() as f:
            self.loads(f.read())

        if isinstance(requirements_file, (text_type, Path)):
            self.filename = requirements_file
def __init__(self):
        self.factory = yui.YUI.widgetFactory()
        self.dialog = self.factory.createPopupDialog()
        mainvbox = self.factory.createVBox(self.dialog)
        frame    = self.factory.createFrame(mainvbox,"Test frame")
        HBox     = self.factory.createHBox(frame)
        self.aboutbutton = self.factory.createPushButton(HBox,"&About")
        self.closebutton = self.factory.createPushButton(self.factory.createRight(HBox), "&Close")