def set_proxy(self, host, port, user=None, password=None):
self._httpclient.set_proxy(host, port, user, password)<EOL>
Sets the proxy server host and port for the HTTP CONNECT Tunnelling.

host:
    Address of the proxy. Ex: '192.168.0.100'
port:
    Port of the proxy. Ex: 6000
user:
    User for proxy authorization.
password:
    Password for proxy authorization.