Function im_subscribe_request_event 

pub fn im_subscribe_request_event(
    endpoint: Option<u16>,
    cluster: Option<u32>,
    event: Option<u32>,
    exchange: u16,
    keep_subscriptions: bool,
) -> Result<Vec<u8>>

Build a SubscribeRequest for an event path (EventRequests, tag 4). Any None field is omitted from the EventPathIB, acting as a wildcard.