How to use the datacite.errors.HttpError function in datacite

"""Synchronize DOI status DataCite MDS."""
        status = None

        try:
            self.api.doi_get(pid.pid_value)
            status = cfg['PIDSTORE_STATUS_REGISTERED']
        except DataCiteGoneError:
            status = cfg['PIDSTORE_STATUS_DELETED']
        except DataCiteNoContentError:
            status = cfg['PIDSTORE_STATUS_REGISTERED']
        except DataCiteNotFoundError:
            pass
        except DataCiteError as e:
            pid.log("SYNC", "Failed with %s" % e.__class__.__name__)
            return False
        except HttpError as e:
            pid.log("SYNC", "Failed with HttpError - %s" % unicode(e))
            return False

        if status is None:
            try:
                self.api.metadata_get(pid.pid_value)
                status = cfg['PIDSTORE_STATUS_RESERVED']
            except DataCiteGoneError:
                status = cfg['PIDSTORE_STATUS_DELETED']
            except DataCiteNoContentError:
                status = cfg['PIDSTORE_STATUS_REGISTERED']
            except DataCiteNotFoundError:
                pass
            except DataCiteError as e:
                pid.log("SYNC", "Failed with %s" % e.__class__.__name__)
                return False