Function starts_with_stream 

pub fn starts_with_stream(paths: &[PathBuf]) -> bool

Whether the Arrow paths are read by converting their streams: when the first is a stream. Only the first is opened. The conversion opens the rest, and leaves the IPC files among them where they are; a stream behind an IPC file is found by any_stream once the scan, which reads every IPC file’s footer, has failed on it.