def get_roles(self):
        """Return all the roles (IAM or User Groups) that can be granted to a safe deposit box.

        Roles are permission levels that are granted to IAM or User Groups.  Associating the id for the write role
          would allow that IAM or User Group to write in the safe deposit box."""
        roles_resp = get_with_retry(self.cerberus_url + '/v1/role',
                                  headers=self.HEADERS)

        throw_if_bad_response(roles_resp)
        return roles_resp.json()