This table represents mitigation action for the respective
threat. A threat is uniquely represented by the threat id,
owner id, controller IP and TIDP group ID and hence
corresponding objects are used as indices.
A row is added to the table when the consumer enforces a
mitigation action as a result of receiving a threat message
from a controller in a TIDP group.
A row is deleted from the table when the consumer removes
the mitigation action taken for the threat received from a
controller in a TIDP group.