/// The operation failed because of a system problem, even though the request was valid.
/// Retry your request.
///
/// The operation failed because you tried to create, update, or delete an object by using
/// an invalid account identifier.
///
/// The operation failed because you tried to delete an object that isn't empty. For example:
///
///
-
///
/// You tried to delete a
WebACL that still contains one or more Rule
/// objects.
///
/// -
///
/// You tried to delete a
Rule that still contains one or more ByteMatchSet
/// objects or other predicates.
///
/// -
///
/// You tried to delete a
ByteMatchSet that contains one or more ByteMatchTuple
/// objects.
///
/// -
///
/// You tried to delete an
IPSet that references one or more IP addresses.
///
///
///
/// The operation failed because the referenced object doesn't exist.
///
/// The operation failed because you tried to delete an object that is still in use. For
/// example:
///
///
-
///
/// You tried to delete a
ByteMatchSet that is still referenced by a Rule.
///
/// -
///
/// You tried to delete a
Rule that is still referenced by a WebACL.
///
///
///
/// The operation failed because you tried to create, update, or delete an object by using
/// a change token that has already been used.
///
