def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
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")