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_lower_bound_checked_changed(self):
        if self.ui.checkBoxLowerBound.isChecked():
            self.ui.spinBoxLowerBound.setEnabled(True)
            self.ui.spinBoxBoundaryNumber.setEnabled(True)
        elif not self.ui.checkBoxUpperBound.isChecked():
            self.ui.spinBoxLowerBound.setEnabled(False)
            self.ui.spinBoxBoundaryNumber.setEnabled(False)
        else:
            self.ui.spinBoxLowerBound.setEnabled(False)