The findByTargetCriterionRequest element cannot have "xsi:nil" as an attribute.
The findByTargetCriterionRequest element in XML instance can be substituted with other elements.
XML Instance
This request retrieves the notifications
matching the supplied criteria. It also retrieves
associated statistics.
If provided, only a maximum of resultsLimit
notifications will be retrieved according to this
request's processing order.
Please see the findByTargetCriterionRequest
type for more details.