Add RealPassThrough model with assert statement

What is the problem?

Often inputs and outputs need an assertion. Mostly between min and max boundary values.

How do we want to solve it? Describe the solution you'd like

Create a model that just passes through the Real value but also assert this value.

Describe alternatives you've considered

Write assert statement in the source code. But this is not a smart option since one mix up graphical and text-based modelling.