code: def delete_snapshot(self, systemId, snapshotGroupId):
          
          #try:
          consistencyGroupIdDict = {'snapGroupId':snapshotGroupId}
          self.conn.connection._check_login()
          response = self.conn.connection._do_post("{}/{}{}/{}".format(self.conn.connection._api_url, "instances/System::", systemId, 'action/removeConsistencyGroupSnapshots'), json=consistencyGroupIdDict)
          #except:
          #    raise RuntimeError("delete_snapshot() - Error communicating wit ScaleIO gateway")
          return response
docs: :param systemId: ID of Cluster
          :param snapshotGroupId: ID of snapshot group ID to be removed
          
          
          /api/instances/System::{id}/action/removeConsistencyGroupSnapshots
          type: POST
          Required:
              snapGroupId
          Return:
              numberOfVolumes - number of volumes that were removed because of this operation