anchor.diff:  * `value()`, the given value will be passed to the validation engine;
   * `iterableValue()`, the given value will be passed to the validation engine and the corresponding property path node (see <<validationapi-constraintviolation>>) will be marked as iterable, i.e. `Node#isInIterable()` returns `true`;
   * `indexedValue()`, the given value will be passed to the validation engine and the corresponding property path node will be marked as iterable and it will have set the given index, i.e. `Node#getIndex()` returns the given index value;
  -* `keyedValue()`, the given value will be passed to the validation engine and the corresponding property path node will  be marked as iterable and it will have set the given key, i.e. `Node#getKey()` returns the given key value
  +* `keyedValue()`, the given value will be passed to the validation engine and the corresponding property path node will  be marked as iterable and it will have set the given key, i.e. `Node#getKey()` returns the given key value.
   
   When passing a non-null node name to any of the receiver methods and the extractor is called in the course of container element validation (and not during cascaded validation),
   a node of kind `CONTAINER_ELEMENT` will be appended to the property path, with `Node#getName()` returning the specified name.
  
positive.code: * [tck-testable]#Only [classname]`ConstraintValidator` implementations targeting annotated elements are considered.#
  * [tck-testable]#Primitive types are considered equivalent to their respective primitive wrapper class.#
  * A [classname]`ConstraintValidator<A, U>` is said to be _compliant_ with [classname]`T` if [classname]`T` is a subtype of [classname]`U` (according to the link:$$http://docs.oracle.com/javase/specs/jls/se8/html/jls-4.html#jls-4.10$$[Java Language Specification 3rd edition chapter 4.10 Subtyping]). Note that [classname]`T` is a subtype of [classname]`U` if [classname]`T` = [classname]`U`.
  * [tck-testable]#If no [classname]`ConstraintValidator` compliant with [classname]`T` is found amongst the [classname]``ConstraintValidator``s listed by the constraint [classname]`A`, an [classname]`UnexpectedTypeException` is raised.#
  * [tck-testable]#A [classname]`ConstraintValidator<A, U>` compliant with [classname]`T` is considered _strictly more specific_ than a [classname]`ConstraintValidator<A, V>` compliant with [classname]`T` if [classname]`U` is a strict subtype of [classname]`V`. [classname]`U` is a strict subtype of [classname]`V` if [classname]`U` is a subtype of [classname]`V` and [classname]`U` != [classname]`V` (according to the link:$$http://docs.oracle.com/javase/specs/jls/se8/html/jls-4.html#jls-4.10$$[Java Language Specification 3rd edition chapter 4.10 Subtyping]).#
  * A [classname]`ConstraintValidator<A, U>` compliant with [classname]`T` is considered maximally specific if no other [classname]`ConstraintValidator<A, V>` compliant with [classname]`T` is strictly more specific than [classname]`ConstraintValidator<A, U>`.
  * [tck-testable]#If more than one maximally specific [classname]`ConstraintValidator` is found, an [classname]`UnexpectedTypeException` is raised.#
  
negative.code: 
  * A `ValueExtractor<T>` is said to be _type-compliant_ with `C'`, if `C'` is a subtype of `T`.
  Note that `C'` is a subtype of `T` if `C'` = `T`.
  * A `ValueExtractor` implementation is said to be _container-element-compliant_ with `C`, if it handles a type parameter that maps to the type argument marked with `@Valid`.
  * If no `ValueExtractor` type-compliant with `C'` and container-element-compliant with `C` is found among the available value extractors, a `ConstraintDeclarationException` is raised.
  * A `ValueExtractor<U>` type-compliant with `C'` is considered _strictly more specific_ than a `ValueExtractor<V>` compliant with `C'` if `U` is a strict subtype of `V`.
  `U` is a strict subtype of `V` if `U` is a subtype of `V` and `U` != `V`.
  * A `ValueExtractor<U>` type-compliant with `C'` is considered maximally specific if no other `ValueExtractor<V>` type-compliant with `C'` is strictly more specific than `ValueExtractor<U>`.
  