Function parse_frame_header 

pub fn parse_frame_header(
    data: &[u8],
) -> Result<(Direction, usize, Transport, String, Timestamp, usize), ParseError>

Parse a frame header line from &[u8].

Expected format: (recv|sent) <N> bytes (from|to) <transport>/<address> at <timestamp>:\n

Returns (Frame header fields, header_len) where header_len includes the trailing \n.