anchor.diff:  The `@RegistryType` can be used to retrieve the `MetricRegistry` for a specific scope.
   The implementation must produce the corresponding `MetricRegistry` specified by the `RegistryType`.
   
  -NOTE:: The implementor can optionally provide a _read_only_ copy of the `MetricRegistry` for _base_ and _vendor_ scopes.
  +NOTE: The implementor can optionally provide a _read_only_ copy of the `MetricRegistry` for _base_ and _vendor_ scopes.
   
   ==== Application Metric Registry
   The implementation must produce the _application_ `MetricRegistry` when no `RegistryType` is provided (`@Default`) or when the `RegistryType` is `APPLICATION`.
  
positive.code: 
  Metadata is exposed in a tree-like fashion with sub-trees for the sub-resources mentioned previously.
  
  *Note:* The implementation should return a 406 response code if the request's HTTP Accept header does not match `application/json`.
  
  Example:
  
  
negative.code: Base metrics is a list of metrics that all vendors need to implement. Optional base metrics are recommended to be implemented but are not required.
  These metrics are exposed under `/metrics/base`.
  
  The following is a list of required and optional base metrics. All metrics are singletons and have `Multi:` set to `false` unless otherwise stated.
  Visit <<meta-data-def>> for the meaning of each key
  
  
  