tests/input/source_test:
tests/input/source_test:

Sketched 3 test cases for characteristic fault source conversion.

The `simple` variation already passes.


Former-commit-id: 3c4fac743984edbfce0a031b578c0ced87384d8b [formerly a7b208cc9e3387b5051db8092674919455476efe]
Former-commit-id: c256906592f5f1a9db18567e3cbeb7299b61432b
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine