types
Look at Single Table Inheritance for more detail
Usage
class Person extends Model {  static entity = 'person'  static types () {    return {      PERSON: Person,      ADULT: Adult    }  }  static fields () {    return {      id: this.attr(null),      name: this.attr('')    }  }}Typescript Declarations
export interface InheritanceTypes {  [key: string]: typeof Model}function $types(): InheritanceTypes