def __init__(self, package, version):
        """Construct a new requirement.

        :param package: the package name.
        :param version: a semver compatible version specification.
        """
        self.package = package
        self.version = version
        if self.version and not re.match(r"[<=>~]", version[:2]):
            self.version = "=={}".format(self.version)
def _on_event_box_enter_notify_event(self, event_box, event):
    if event.detail != gtk.gdk.NOTIFY_INFERIOR:
      self._hbox_buttons.show()