Catch up with the latest API to fix the build error in #7156

Change-Id: Ia51be04f9f5ed5381e524a405944bf3a67f0c034

@@ -15,7 +15,6 @@
  */
 package org.onosproject.net.intent.impl.compiler;
 
-import com.google.common.collect.ImmutableSet;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
@@ -644,12 +643,8 @@ public class OpticalCircuitIntentCompiler implements IntentCompiler<OpticalCircu
      * @return set of TributarySlots available on the connect point
      */
     Set<TributarySlot> findTributarySlotsOnCp(ConnectPoint cp) {
-        return ImmutableSet.of(); // temporary fix for build
-        // FIXME: below changes break the build due to conflicting changes on Resource, which obsoleted Resource#last()
-//        return resourceService.getAvailableResources(Resources.discrete(cp.deviceId(), cp.port()).id())
-//                .stream()
-//                .filter(x -> x.last() instanceof TributarySlot)
-//                .map(x -> (TributarySlot) x.last())
-//                .collect(Collectors.toSet());
+        return resourceService.getAvailableResourceValues(
+                Resources.discrete(cp.deviceId(), cp.port()).id(),
+                TributarySlot.class);
     }
 }