'Test the ability to retrieve the PR associated with an issue.'

def test_pull_request(self):

    cassette_name = self.cassette_name('pull_request')
    with self.recorder.use_cassette(cassette_name):
        issue = self.gh.issue('sigmavirus24', 'github3.py', 301)
        assert (issue is not None)
        pull_request = issue.pull_request()
    assert isinstance(pull_request, github3.pulls.PullRequest)
