without_internet simulates the situation when any network request will
fail, as in when you are without an internet connection. Any HTTP request
through the verb functions in
httr will raise an error.
Code to run inside the mock context
The result of
The error message raised has a well-defined shape, made of three
elements, separated by space: (1) the request
method (e.g. "GET"); (2) the request URL; and
(3) the request body, if present. The verb-expectation functions,
expect_POST(), look for this shape.
block_requests() to enable mocking on its own (not in a context)