'Get a particular sync session.
:param array: the array serial number
:param source_device_id: source device id
:param snap_name: the snapshot name
:param target_device_id: the target device id
:returns: sync session -- dict, or None'

def get_sync_session(self, array, source_device_id, snap_name, target_device_id):

    session = None
    linked_device_list = self.get_snap_linked_device_list(array, source_device_id, snap_name)
    for target in linked_device_list:
        if (target_device_id == target['targetDevice']):
            session = target
    return session
