@Override
	public Field getKeyField(int index) throws IOException {
		Field key = keyType.newField();
		key.read(buffer, buffer.getInt(BASE + (index * ENTRY_SIZE)));
		return key;
	}
Store the key offset within the buffer for the specified key index.
@param index key index
@param offset key offset
Ghidra/Framework/DB/src/main/java/db/VarKeyInteriorNode.java