Refined the usage of all_equal
Refined the usage of all_equal


Former-commit-id: de7e47dd7dfed78f46e01d2c4691ff9da0adea4c [formerly b1e3c5129e723a18fb7d7db575f1e09f7728e0b5]
Former-commit-id: 5769af39b026357154ba4f1f3ae97806856611b2
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine