Make fields private to get classes immutable

Change-Id: Ib2d6c013b8c027b2ddc6a7d1cb204627a2dd7b19

@@ -69,15 +69,15 @@ public final class ContinuousResource implements Resource {
 
     @Override
     public List<Object> components() {
-        return id.components;
+        return id.components();
     }
 
     @Override
     public Object last() {
-        if (id.components.isEmpty()) {
+        if (id.components().isEmpty()) {
             return null;
         }
-        return id.components.get(id.components.size() - 1);
+        return id.components().get(id.components().size() - 1);
     }
 
     @Override

@@ -30,7 +30,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
  */
 @Beta
 public final class ContinuousResourceId extends ResourceId {
-    final ImmutableList<Object> components;
+    private final ImmutableList<Object> components;
 
     // for printing purpose only (used in toString() implementation)
     private final String name;
@@ -45,6 +45,10 @@ public final class ContinuousResourceId extends ResourceId {
         this.name = last.getSimpleName();
     }
 
+    ImmutableList<Object> components() {
+        return components;
+    }
+
     /**
      * {@inheritDoc}
      *

@@ -65,15 +65,15 @@ public final class DiscreteResource implements Resource {
 
     @Override
     public List<Object> components() {
-        return id.components;
+        return id.components();
     }
 
     @Override
     public Object last() {
-        if (id.components.isEmpty()) {
+        if (id.components().isEmpty()) {
             return null;
         }
-        return id.components.get(id.components.size() - 1);
+        return id.components().get(id.components().size() - 1);
     }
 
     @Override

@@ -31,7 +31,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
  */
 @Beta
 public final class DiscreteResourceId extends ResourceId {
-    final ImmutableList<Object> components;
+    private final ImmutableList<Object> components;
 
     DiscreteResourceId(ImmutableList<Object> components) {
         this.components = components;
@@ -41,6 +41,10 @@ public final class DiscreteResourceId extends ResourceId {
         this.components = ImmutableList.of();
     }
 
+    ImmutableList<Object> components() {
+        return components;
+    }
+
     @Override
     public DiscreteResourceId child(Object child) {
         checkArgument(!(child instanceof Class<?>));