Function git_protocol::fetch

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

Perform a ‘fetch’ operation with the server using transport, with delegate handling all server interactions.

• authenticate(operation_to_perform) is used to receive credentials for the connection and potentially store it if the server indicates ‘permission denied’. Note that not all transport support authentication or authorization.
• progress is used to emit progress messages.

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