code: def repo_def_matches_reality(juicer_def, pulp_def):
      
      return juicer.common.Repo.RepoDiff(juicer_repo=juicer_def, pulp_repo=pulp_def)
docs: Compare a juicer repo def with a given pulp definition. Compute and
      return the update necessary to make `pulp_def` match `juicer_def`.
  
      `juicer_def` - A JuicerRepo() object representing a juicer repository
      `pulp_def` - A PulpRepo() object representing a pulp repository