Is there a good way to execute SPPL model source code while having it rely on a previously existing model? For example, assume I have an SPPL model m (of type ProductSPE) which models variables a and b.
I have this source code source in form of a string:

if a < 17 
    c ~= bernoulli(p=0.1)

else:
    c ~= bernoulli(p=0.9)

which relies on a being defined but which would otherwise compile fine if I run:

SPPL_Compiler(source).execute_module().model

Obviously, without knowing about m it won't compile because the compiler doesn't know about a. Is there a good way to tell the compiler about a model (like m) as a starting point? i.e. something like this:

SPPL_Compiler(m, source).execute_module().model