Having a setup function and >1 iterations is not possible

[romanrdgz]

As coded in src/pytest_benchmark/fixture.py:

if iterations > 1 and setup:
            raise ValueError("Can't use more than 1 `iterations` with a `setup` function.")

I have not found any reference to this in documentation. Moreover, the initial pedantic example in documentation suggests using a setup function and 10 iterations, which is impossible.

[arekbulski]

I second this request, to allow multiple benchmark(...) lines per test case. Multiple calls should be summed/added.