'Creates a new KeyVaultAuthBase instance used for handling authentication challenges, by hooking into the request AuthBase
extension model.
:param authorization_callback: A callback used to provide authentication credentials to the key vault data service.
This callback should take three str arguments: authorization uri, resource, and scope, and return
a tuple of (token type, access token).
return token[\'token_type\'], token[\'access_token\']'

def __init__(self, authorization_callback):

    self._callback = authorization_callback
    self._token = None
    self._thread_local = threading.local()
    self._thread_local.pos = None
    self._thread_local.auth_attempted = False
