protected long optionalFooterPosition() throws CartInvalidCartException {
		return optionalFooterPosition;
	}
Get the position of the optional footer. Should be 0 if no optional footer is
available.

@return The position of the optional footer, 0 if no optional footer.
@throws CartInvalidCartException If the footer object is not valid.
Ghidra/Features/FileFormats/src/main/java/ghidra/file/formats/cart/CartV1Footer.java