anchor.diff:  *   `version` the schema version;
   *   `definition` the schema definition.
   
  -===== `GET /{subject}/{format}`
  +`GET /{subject}/{format}`
   
   Retrieve a list of existing schema by its subject and format.
   
  
positive.code: *   `version` the schema version;
  *   `definition` the schema definition.
  
  ===== `GET /schemas/{id}`
  
  Retrieve an existing schema by its id.
  
  
negative.code: *   `version` the schema version;
  *   `definition` the schema definition.
  
  `GET /{subject}/{format}/{version}`
  
  Retrieve an existing schema by its subject, format and version.
  
  