1package entity
 2
 3type Interface interface {
 4	// Id return the Entity identifier
 5	//
 6	// This Id need to be immutable without having to store the entity somewhere (ie, an entity only in memory
 7	// should have a valid Id, and it should not change if further edit are done on this entity).
 8	// How to achieve that is up to the entity itself. A common way would be to take a hash of an immutable data at
 9	// the root of the entity.
10	// It is acceptable to use such a hash and keep mutating that data as long as Id() is not called.
11	Id() Id
12}