public void setBaseOffset(int tableIndex, Long offset) {
		PlaceholderVirtualBaseTableEntry entry = entry(tableIndex);
		if (entry == null) {
			entry = new PlaceholderVirtualBaseTableEntry(offset);
			entryByTableIndex.put(tableIndex, entry);
			maxTableIndexSeen = Integer.max(maxTableIndexSeen, tableIndex);
		}
		else {
			entry.setOffset(offset);
		}
	}
Constructor
@param owner the class that owns the table
@param parentage the parentage of the base class(es) of the table
Ghidra/Features/PDB/src/main/java/ghidra/app/util/pdb/classtype/PlaceholderVirtualBaseTable.java