@Target({TYPE,PACKAGE})
@NotNull
@Nonnull
@TypeQualifierDefault({METHOD,PARAMETER})
@Documented
@Retention(RUNTIME)
public @interface NonNullApi

Marks a type or a whole package as providing a non-null API by default. All parameter and return types are assumed to be Nonnull unless specifically marked as Nullable. All types of an annotated package inherit the package rule. Subpackages do not inherit nullability rules and must be annotated.