Let's now see an example of validating constraints on entities. First of all, we can run the validate() method on an entire entity, which will then use its TypedData wrapper (EntityAdapter) to run a validation on all the fields on the entity plus any of the entity-level constraints. The latter can be added via the EntityType plugin definition (the annotation). For example, the Comment entity type has this bit:
* constraints = {* "CommentName" = {}* }
This means that the constraint plugin ID is CommentName and it takes no parameters (since the braces are empty). We can even add constraints to entity types that do not "belong" to us by implementing hook_entity_type_alter(), for example:
function my_module_entity_type_alter(array ...
