e.g.:

```python
from requests.packages.urllib3.util.retry import Retry
import requests_unixsocket

sess = requests_unixsocket.Session()

HTTP_REQUEST_RETRIES = 3
HTTP_RETRY_BACKOFF_FACTOR = 0.3
HTTP_RETRY_FORCELIST = (404, 500, 502, 504)

retry = Retry(total=HTTP_REQUEST_RETRIES,
              read=HTTP_REQUEST_RETRIES,
              connect=HTTP_REQUEST_RETRIES,
              backoff_factor=HTTP_RETRY_BACKOFF_FACTOR,
              status_forcelist=HTTP_RETRY_FORCELIST)

adapter = requests_unixsocket.UnixAdapter(max_retries=retry)
sess.mount('http+unix://', adapter)

print(sess.get('http+unix://%2Fvar%2Frun%2Fdocker.sock/this-does-not-exist'))
```

Fixes: GH-37