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: net.rs
    path of file: ./repos/conwayste/netwayste/src
    
    the code of the file until where you have to start completion: /*
 * Herein lies a networking library for the multiplayer game, Conwayste.
 *
 * Copyright (C) 2018-2019 The Conwayste Developers
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of  MERCHANTABILIT
    
    fn insert_into_rx_queue(&mut self, index: Option<usize>, item: T) -> bool {
        let mut exists: bool = false;
        if let Some(insertion_index) = index {
            if insertion_index != MATCH_FOUND_SENTINEL {
                if cfg!(test) {
                    self.as_queue_type_mut().insert(insertion_index, item.clone());
                    self.attempts.push_back(NetAttempt::new());
                }
            }
            if !(cfg!(test)) {
                self.as_queue_type_mut().insert(insertion_index, item);
                self.attempts.push_back(NetAttempt::new());
            }
        } else {
            exists = true;
        } // Packet is present in queue, hence None.
        return exists;
    }