code: public int delete(CMAApiKey key) {
      assertNotNull(key, "key");
      final String space = getSpaceIdOrThrow(key, "key");
      final String id = getResourceIdOrThrow(key, "key");
  
      return service.delete(space, id).blockingFirst().code();
    }
docs: Delete a given api key from the configured space.
  
  @param key the key to be deleted.
  @return 204 upon success.
  @throws IllegalArgumentException if key is null.
  @throws IllegalArgumentException if key's spaceId is null.