tw.err = tw.writeUSTARHeader(&tw.hdr)
		return tw.err
	case allowedFormats.has(FormatPAX):
		tw.err = tw.writePAXHeader(&tw.hdr, paxHdrs)
		return tw.err
	case allowedFormats.has(FormatGNU):
		tw.err = tw.writeGNUHeader(&tw.hdr)
		return tw.err
	default:
		return err // Non-fatal error
	}
}

func (tw *Writer) writeUSTARHeader(hdr *Header) error {
	// Check if we can use USTAR prefix/suffix splitting.