pub trait Connection {
// Required methods
fn set_send_package_impl(&mut self, handle: Box<dyn Fn(Vec<u8>)>);
fn send_package(&self, package: Vec<u8>);
fn set_recv_package_impl(&mut self, handle: Box<dyn Fn(Vec<u8>)>);
fn on_recv_package(&self, package: Vec<u8>);
}