"Rapidminer - Operators - implementation (neural net)"

Hello,

I am newbie in rapidminer, so maybe I will ask some dummy questions.
Can I somewhere find how rapidminer operators work? How they are implemented?

For example, I am interested in neural networks. When I run "neural net" operator, besides normal nodes, it creates threshold node. In the output I can see weights, but I don't know how to find out threshold node value.

Thank you for an answers