@staticmethod
def get_geofence_radius(policy_contract_dict):
    """
        Extract geofence radius from supplied policy contract.

        :param policy_contract_dict: The contract of interest
        :type policy_contract_dict: dict
        :return: radius of geofence
        :rtype: string
        """
    try:
        radius = policy_contract_dict['geofence']['candidate_config']['radius']
        return radius
    except KeyError:
        return None
