The following classes are available globally.
An instance of the Filter class is used to filter query results All filters are automatically converted into SQLite statements when querying the database.
To make filtering easier, and backwards compatibility, it is possible to instantiate a filter object as a dictionary literal
Return any objects with the name ‘Ghost’
let filter: Filter = ["name": "Ghost"]
let filter = Filter.equal("name", value: "Ghost")
public class Filter: DictionaryLiteralConvertible