public long getOffset(int index, DWARFCompilationUnit cu) throws IOException {
		long base = baseOffsetFunc.apply(cu);
		DWARFIndirectTableHeader header = lookupMap.get(base);
		if (header == null) {
			throw new IOException(
				"Invalid base %d for compUnit %x".formatted(base, cu.getStartOffset()));
		}
		return header.getOffset(index, reader);
	}
Returns the offset of an item, based on its index in a particular header (which is found
by the controlling CU)

@param index index of the item
@param cu {@link DWARFCompilationUnit}
@return long offset of the item.  Caller responsible for reading the item themselves
@throws IOException if error reading table data
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/DWARFIndirectTable.java