You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sticky_parameters.rs
    path of file: ./repos/matrix-rust-sdk/crates/matrix-sdk/src/sliding_sync
    
    the code of the file until where you have to start completion: //! Sticky parameters are a way to spare bandwidth on the network, by sending
//! request 
    
    pub fn maybe_apply(&mut self, req: &mut D::Request, txn_id: &mut LazyTransactionId) {
        if self.invalidated {
            let txn_id = txn_id.get_or_create();
            self.txn_id = Some(txn_id.to_owned());
            self.data.apply(req);
        }
    }