Added docstrings
Added docstrings


Former-commit-id: 798dcbeee2c7320733c131d73fac3355a456d1d2 [formerly 343f8323e996abc0c233efc5d8e57205f41715ad]
Former-commit-id: 513e33b363913615dd19e3c670a432641b7f667c
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine