Use lower bound wildcard for API to be more flexible

Change-Id: Ia6bcec5afb2e872b55bae4bbd9139ad35ce01284
diff --git a/core/net/src/main/java/org/onosproject/net/newresource/impl/ResourceManager.java b/core/net/src/main/java/org/onosproject/net/newresource/impl/ResourceManager.java
index 878f202..bbc8678 100644
--- a/core/net/src/main/java/org/onosproject/net/newresource/impl/ResourceManager.java
+++ b/core/net/src/main/java/org/onosproject/net/newresource/impl/ResourceManager.java
@@ -80,7 +80,7 @@
 
     @Override
     public List<ResourceAllocation> allocate(ResourceConsumer consumer,
-                                             List<Resource> resources) {
+                                             List<? extends Resource> resources) {
         checkNotNull(consumer);
         checkNotNull(resources);
 
@@ -171,14 +171,14 @@
     }
 
     @Override
-    public boolean register(List<Resource> resources) {
+    public boolean register(List<? extends Resource> resources) {
         checkNotNull(resources);
 
         return store.register(resources);
     }
 
     @Override
-    public boolean unregister(List<ResourceId> ids) {
+    public boolean unregister(List<? extends ResourceId> ids) {
         checkNotNull(ids);
 
         return store.unregister(ids);
diff --git a/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/MockResourceService.java b/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/MockResourceService.java
index 4083f5b..b3ad768 100644
--- a/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/MockResourceService.java
+++ b/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/MockResourceService.java
@@ -44,7 +44,7 @@
     private final Map<Resource, ResourceConsumer> assignment = new HashMap<>();
 
     @Override
-    public List<ResourceAllocation> allocate(ResourceConsumer consumer, List<Resource> resources) {
+    public List<ResourceAllocation> allocate(ResourceConsumer consumer, List<? extends Resource> resources) {
         assignment.putAll(
                 resources.stream().collect(Collectors.toMap(x -> x, x -> consumer))
         );