Function git_protocol::fetch

pub fn fetch<F, P>(
    transport: impl Transport, 
    delegate: &mut impl Delegate, 
    authenticate: F, 
    progress: P
) -> Result<(), Error> where
    F: FnMut(Action<'_>) -> Result,
    P: Progress,
    <P as Progress>::SubProgress: Send + 'static,
    <<P as Progress>::SubProgress as Progress>::SubProgress: Send + 'static, 

Note that depending on the delegate, the actual action peformed can be ls-refs, clone or fetch.