def METHOD_NAME(self):
    formatted = reporter.format_as_csv(self.empty_header, self.empty_data)
    # 1 header line, no separation line + 0 data lines
    assert len(formatted.splitlines()) == 1 + 0
    formatted = reporter.format_as_csv(self.metrics_header, self.metrics_data)
    # 1 header line, no separation line + 3 data lines
    assert len(formatted.splitlines()) == 1 + 4