<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
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<USER_TASK:>
Description:
 def login(self, email, password):
 """Authenticate a user with SignalFx to acquire a session token. Note that data ingest can only be done with an organization or team API access token, not with a user token obtained via this method. Args: email (string):
 the email login password (string):
 the password Returns a new, immediately-usable session token for the logged in user. """

        r = requests.post('{0}/v2/session'.format(self._api_endpoint),
                          json={'email': email, 'password': password})
        r.raise_for_status()
        return r.json()['accessToken']