protected Long getResourceId(Request request, Predicate predicate) {
    return null;
  }
Gets the identifier, relative to the the effected ResourceType that is effected by the relevant
request and predicate.
<p/>
Implementations should override this method return the proper resource id.

@param request   the request object which defines the desired set of properties
@param predicate the predicate object which can be used to indicate the filter
@return a resource id; or null to indicate any or all resources of the relevant type
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/AbstractAuthorizedResourceProvider.java