code: public static Map<String,Collection<IConditional>> getPropertyReferences( FunctionInputDef function)
      {
      SetValuedMap<String,IConditional> refs = MultiMapUtils.newSetValuedHashMap();
  
      conditionals( function)
        .forEach( conditional -> propertiesReferenced( conditional.getCondition()).forEach( p -> refs.put( p, conditional)));
      
      return refs.asMap();
      }
docs: Maps every property in the given FunctionInputDef to the conditional elements that reference it.