This example generates an ATL execution trace in a weaving model. We create a higher-order
transformation that takes an ATL transformation as input (e.g., Class to Relational) and
produces an ATL transforamtion as output. The output ATL transforms Class to Relational
models, and additionally generates a traceability model. The traceability model conforms
to a traceability model that is an exentension to the core weaving metamodel.