existingPolicySet := mp.policySet()
	policiesToUpdate := set.CreateStringSet(policies...)
	var newPolicySet set.StringSet
	newPolicyMapping := mp
	if isAttach {
		// new policies to attach => inputPolicies - existing (set difference)
		policiesToUpdate = policiesToUpdate.Difference(existingPolicySet)
		// validate that new policies to add are defined.
		for _, p := range policiesToUpdate.ToSlice() {