How to step into simpeg function in debug mode?

I want to step into the function LinearSimulation(Line,61) using F11. but the vscode jump into another python file named , which is not the that includes the goal function LinearSimulation.

Why this happen, and how can I trace the goal function LinearSimulation to see how it works?

Someone can give any tips?really appreciate.

60:# In[Defining the Simulation]
61:sim = simulation.LinearSimulation(mesh,G=G,model_map=model_map)
62:std = 0.1
64:data_obj = sim.make_synthetic_data(true_model, realtive_error=std,add_noise=True)