builder

Returns a typed factory for constructing the underlying ksl.simulation.Model.

The returned ModelBuilderIfc already carries the engine's standard build signature, accepting an optional configuration map and optional ExperimentRunParametersIfc. The lazy descriptor extractor invokes builder().build(null, null).modelDescriptor(); GUI consumers invoke the builder with whatever inputs the user has authored.

Implementations should be cheap to call but need not be idempotent — each call may return a fresh builder.