'Record the iSCSI MCS topology.
# R model with mcs, but it not working with iSCSI multipath
mcs_dict = {
\'slot_a\': {
\'0\': [\'0\', \'1\'],
\'1\': [\'2\']
\'slot_b\': {
\'0\': [\'0\', \'1\'],
\'1\': [\'2\']
# G model with mcs
mcs_dict = {
\'slot_a\': {
\'0\': [\'0\', \'1\'],
\'1\': [\'2\']
\'slot_b\': {}'

def _update_mcs_dict(self, channel_id, mcs_id, controller):

    if (mcs_id not in self.mcs_dict[controller]):
        self.mcs_dict[controller][mcs_id] = []
    self.mcs_dict[controller][mcs_id].append(channel_id)
