Making the DistancesContext read-only
Making the DistancesContext read-only


Former-commit-id: 306a7609bca1b7b37e5bfa80d02f89f0a03f74de [formerly b66f12487649c24d008d14e6ca7c49bda30fb1de]
Former-commit-id: f23fcd02ac0349df5387a1e80bd01352596b17a0
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine