mustBeOverridden top-level constant Null safety

_MustBeOverridden const mustBeOverridden

Used to annotate an instance member m declared on a class or mixin C. Indicates that every subclass of C, concrete or abstract, must directly override m.

This annotation places no restrictions on the overriding members. In particular, it does not require that the overriding members invoke the overridden member. The annotation mustCallSuper can be used to add that requirement.

Tools, such as the analyzer, can provide feedback if

• the annotation is associated with anything other than an instance member (a method, operator, field, getter, or setter) of a class or of a mixin, or
• the annotation is associated with a member m in class or mixin C, and there is a class or mixin D which is a subclass of C (directly or indirectly), and D does not directly declare a concrete override of m and does not directly declare a concrete override of noSuchMethod.

Implementation

const _MustBeOverridden mustBeOverridden = _MustBeOverridden();