NonNull

@MustBeDocumented
@Retention(value = AnnotationRetention.BINARY)
@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER, AnnotationTarget.VALUE_PARAMETER, AnnotationTarget.FIELD, AnnotationTarget.LOCAL_VARIABLE, AnnotationTarget.ANNOTATION_CLASS, AnnotationTarget.FILE])
@Target(value = [ElementType.METHOD, ElementType.PARAMETER, ElementType.FIELD, ElementType.LOCAL_VARIABLE, ElementType.ANNOTATION_TYPE, ElementType.PACKAGE])
public annotation NonNull

Denotes that a parameter, field or method return value can never be null.

This is a marker annotation and it has no specific attributes.