ConnectionError: HTTPSConnectionPool(host='api.domo.com', port=443):

[tianke0711]

Hi I used the
domo = Domo(client_id, client_secret, api_host=api_host)
Before I used it and it was good.
but recently there is connection error:

ConnectionError: HTTPSConnectionPool(host='api.domo.com', port=443): Max retries exceeded with url: /oauth/token?grant_type=client_credentials (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x7f57597e1dd8>: Failed to establish a new connection: [Errno 110] Connection timed out',))

I want to know what caused it, is it possible caused by the proxy?