This model demonstrates the SDF DDI plugin.
[DDI: domain-dependent interpreter]
The SDF DDI plugin configures the input/output token rates for each port depending
on a simple analysis of the actor definition. It will detect non-SDF actors and
create an error message.
Modify the parameters of the A, B, and Upsample actors and try to run the model.
As the A actor shows, whether an actor in fact *is* an SDF actor may depend on
its parameter values. Therefore the SDF DDI will test this condition when the
model is about to be run, and signal an error if it is found to be violated.