person.createIndex("Person.name", INDEX_TYPE.UNIQUE, "name");
OClass customer = schema.createClass("Customer", person);
customer.createProperty("totalSold", OType.DECIMAL);
OClass provider = schema.createClass("Provider", person);
provider.createProperty("totalPurchased", OType.DECIMAL);
new ODocument("Customer").fields("name", "Jay", "surname", "Miner").save();
new ODocument("Customer").fields("name", "Luke", "surname", "Skywalker").save();
new ODocument("Provider").fields("name", "Yoda", "surname", "Nothing").save();