When you want to create, update, or delete AWS WAF objects, get a change token and include the change token in the create, update, or delete request. Change tokens ensure that your application doesn't submit conflicting requests to AWS WAF.
Each create, update, or delete request must use a unique change token. If your application submits a GetChangeToken request and then submits a second GetChangeToken request before submitting a create, update, or delete request, the second GetChangeToken request returns the same value as the first GetChangeToken request.
When you use a change token in a create, update, or delete request, the status of the change token changes to PENDING, which indicates that AWS WAF is propagating the change to all AWS WAF servers. Use GetChangeTokenStatus to determine the status of your change token.
/// The operation failed because of a system problem, even though the request was valid.
/// Retry your request.
///
