def METHOD_NAME(monkeypatch):
    assert os.getenv('DISTRIBUTION_URL') is None
    assert get_files.get_download_url('myBucket', 'myKey') == 'https://myBucket.s3.myRegion.amazonaws.com/myKey'
    monkeypatch.setenv('DISTRIBUTION_URL', '')
    assert get_files.get_download_url('myBucket', 'myKey') == 'https://myBucket.s3.myRegion.amazonaws.com/myKey'
    monkeypatch.setenv('DISTRIBUTION_URL', 'https://foo.com/')
    assert get_files.get_download_url('myBucket', 'myKey') == 'https://foo.com/myKey'
    monkeypatch.setenv('DISTRIBUTION_URL', 'https://foo.com')
    assert get_files.get_download_url('myBucket', 'myKey') == 'https://foo.com/myKey'