Added comments [skip CI]
Added comments [skip CI]


Former-commit-id: a5eb21e778a616b689451e7698ce8a165b83ffb8 [formerly b932abdb7400335b2cd0ff5da47750b66830ef41]
Former-commit-id: b3a26f61954f854ac57d0dbfbda761629ac5ee57
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine