MIN Remove repeated statement
ENH Emission snippets for advanced exercise
ENH Fix snippets
ENH Implement first version

Partial emissions moved to separate file
ENH Use mapper_final method
ENH Make the code match the guide
ENH More descriptive name
ENH Fix EM Step
ENH Right loading method for this code
ENH More advanced emissions
BUG Fix loading of pickle
ENH Cleanup: this is emstep.py now