static VirtualBaseTableEntry parseVbtEntryFromMemory(Memory memory, Address address,
			int ordinal, int size) throws PdbException {
		if (size != 4 && size != 8) {
			throw new IllegalArgumentException("Invalid size (" + size + "): must be 4 or 8.");
		}
		Address readAddress = address.add(ordinal * size);
		long offset;
		try {
			offset = (size == 4) ? (long) memory.getInt(readAddress) : memory.getLong(readAddress);
		}
		catch (MemoryAccessException e) {
			throw new PdbException(
				"MemoryAccessException while trying to parse virtual base table entry at address: " +
					readAddress);
		}
		return new VirtualBaseTableEntry(offset);
	}
Returns the offset from the virtual base table entry
@param address Address of virtual base table
@param ordinal index into table
@param size size of a vbt entry offset value
@return the offset
@throws PdbException if no table exists for address or no entry exists for ordinal
Ghidra/Features/PDB/src/main/java/ghidra/app/util/pdb/pdbapplicator/PdbVbtManager.java