def __repr__(self):
        return "<Requirement(package={package}, version='{version}')>".format(
            package=self.package, version=self.version)
def __get_linearForce_title_keys(lf):
    if 'force_r' in lf:
        return ['Force r', 'Force z'], ['force_r', 'force_z']
    return ['Force x', 'Force y'], ['force_x', 'force_y']