After initializing the Pusheo object, you can subscribe to a channel.
A channel can be any valid alphanumeric string. ‘lost_messages_call_interval’ specifies the lost messages call interval. Pusheo automatically checks for lost messages and delivers them to you. You also need to specify callback functions at this stage as follows:
echo $pusheo->subscribe(
array(
'channel' => "12345",
'open' => "open",
'message' => "message",
'message_sent' => "message_sent",
'close' => "close",
'error' => "error",
'lost_messages_call' => true,
'lost_messages_call_interval' => 10000
));