anchor.diff:  include::{validation-api-source-dir}javax/validation/metadata/ContainerDescriptor.java[lines=7..8;11..-1]
   ----
   
  -[tck-testable]#`getContainerElementTypes()` returns a list of descriptors representing all the type arguments of the container type,
  -in the order of their declaration.#
  -
  -[tck-testable]#The `ContainerElementTypeDescriptor` interface describes the potential container element constraints applied to one type argument of a container type.#
  -
  -This interface is returned by `ContainerDescriptor.getContainerElementTypes()`.
  +[tck-testable]#If a given element is of a container type, `getConstrainedContainerElementTypes()` returns a set with descriptors representing those container element types that either host at least one constraint or are marked with `@Valid`.#
  +[tck-testable]#The returned set will be empty if the given element is not of a container type or is of a container type but has no element types that are constrained or marked with `@Valid`.#
  +In the context of properties and method return values, container element types of super-types are considered.
  +
  +[tck-testable]#The `ContainerElementTypeDescriptor` interface describes the potential container element constraints applied to one element type of a container.#
  +
  +This interface is returned by `ContainerDescriptor.getConstrainedContainerElementTypes()`.
   
   [source, JAVA, indent=0]
   ----
  
positive.code: ----
  
  [tck-testable]#`getTypeArgumentIndex()` returns the index of the type argument corresponding to this descriptor instance.#
  
  [[constraintmetadata-constraintdescriptor]]
  === ConstraintDescriptor
  
negative.code: [[constraintmetadata-containerdescriptor]]
  === ContainerDescriptor and ContainerElementTypeDescriptor
  
  The `ContainerDescriptor` interface describes those elements that can be of a container type, e.g. `List` or `Map`, and as such may host container element constraints (see <<constraintdeclarationvalidationprocess-containerelementconstraints>>) or have container element types that are marked with `@Valid`.
  
  `ContainerDescriptor` is extended by `PropertyDescriptor`, `ParameterDescriptor`, `ReturnValueDescriptor` and `ContainerElementTypeDescriptor`.
  
  