fix mock calls to avoid importing exposure more than once
fix mock calls to avoid importing exposure more than once


Former-commit-id: 1b5d4335db9d46d8b082b8722599d693532f7022 [formerly 1b5d4335db9d46d8b082b8722599d693532f7022 [formerly b61f1dffdffc5631b50247ad2d7caf493c24bd43]]
Former-commit-id: f9057da9e0a6c81bdcf171517f000db43460f243
Former-commit-id: 4db0e135c1abaa0837c127d0d1187d2080710975
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine