etag

(Output) An opaque tag indicating the current version of the policy, used for concurrency control. This field is ignored if used in a CreatePolicy request. When the policyis returned from either a GetPolicyor a ListPoliciesrequest, this etagindicates the version of the current policy to use when executing a read-modify-write loop. When the policy is returned from a GetEffectivePolicyrequest, the etag` will be unset.