Function parse 

pub fn parse(bytes: &[u8]) -> Result<Header, FitsError>

Parse one FITS header unit from raw bytes.

Reads 80-byte cards in order, stops at END, and retains every card (including commentary, HIERARCH, and unrecognized cards) so untouched cards serialize verbatim. CONTINUE runs are reassembled into a single logical value.

Examples

let mut bytes = Vec::new();
for card in ["OBJECT  = 'M31     '", "EXPTIME =                120.0", "END"] {
    let mut c = card.as_bytes().to_vec();
    c.resize(80, b' ');
    bytes.extend(c);
}

let header = fits_header::parse(&bytes).unwrap();
assert_eq!(header.get_str("OBJECT").unwrap(), Some("M31"));
assert_eq!(header.get::<f64>("EXPTIME").unwrap(), Some(120.0));