code: def compute(mechanism, subsystem, purviews, cause_purviews,
                  effect_purviews):
          
          concept = subsystem.concept(mechanism,
                                      purviews=purviews,
                                      cause_purviews=cause_purviews,
                                      effect_purviews=effect_purviews)
          # Don't serialize the subsystem.
          # This is replaced on the other side of the queue, and ensures
          # that all concepts in the CES reference the same subsystem.
          concept.subsystem = None
          return concept
docs: Compute a |Concept| for a mechanism, in this |Subsystem| with the
          provided purviews.