Fixed a few comments and docstring
Fixed a few comments and docstring


Former-commit-id: 241d6ae63f68e6fcfa0faf0c24c6ea375835ee4c [formerly ba6faca7130e9a99e1dee30f76e7aa1533e76928]
Former-commit-id: b75e229e5d31a824fd0e6387c640e1efa68e5a9c
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine