#NEWLINE# @ ndb . tasklet #NEWLINE# def _make_token_async( scopes , service_account_id ) : #NEWLINE# #INDENT# 'Get a fresh authentication token.\n\n  Args:\n    scopes: A list of scopes.\n    service_account_id: Internal-use only.\n\n  Returns:\n    An tuple (token, expiration_time) where expiration_time is\n    seconds since the epoch.\n  ' #NEWLINE# rpc = app_identity . create_rpc ( ) #NEWLINE# app_identity . make_get_access_token_call ( rpc , scopes , service_account_id ) #NEWLINE# ( token , expires_at ) = ( yield rpc ) #NEWLINE# raise ndb . Return ( ( token , token ) )