Add DefaultLinkResourceRequest implementation.
diff --git a/core/api/src/main/java/org/onlab/onos/net/resource/DefaultLinkResourceRequest.java b/core/api/src/main/java/org/onlab/onos/net/resource/DefaultLinkResourceRequest.java
new file mode 100644
index 0000000..38f90c1
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/resource/DefaultLinkResourceRequest.java
@@ -0,0 +1,118 @@
+package org.onlab.onos.net.resource;
+
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.intent.IntentId;
+
+import com.google.common.collect.ImmutableSet;
+
+/**
+ * Implementation of {@link LinkResourceRequest}.
+ */
+public final class DefaultLinkResourceRequest implements LinkResourceRequest {
+
+    private final IntentId intentId;
+    private final Collection<Link> links;
+    private final Set<ResourceRequest> resources;
+
+    /**
+     * Creates a new link resource request with the given ID, links, and
+     * resource requests.
+     *
+     * @param intentId intent ID related to this request
+     * @param links a set of links for the request
+     * @param resources a set of resources to be requested
+     */
+    private DefaultLinkResourceRequest(IntentId intentId,
+            Collection<Link> links,
+            Set<ResourceRequest> resources) {
+        this.intentId = intentId;
+        this.links = ImmutableSet.copyOf(links);
+        this.resources = ImmutableSet.copyOf(resources);
+    }
+
+    @Override
+    public IntentId intendId() {
+        return intentId;
+    }
+
+    @Override
+    public Collection<Link> links() {
+        return links;
+    }
+
+    @Override
+    public Set<ResourceRequest> resources() {
+        return resources;
+    }
+
+    /**
+     * Returns builder of link resource request.
+     *
+     * @param intentId intent ID related to this request
+     * @param links a set of links for the request
+     * @return builder of link resource request
+     */
+    public static LinkResourceRequest.Builder builder(
+            IntentId intentId, Collection<Link> links) {
+        return new Builder(intentId, links);
+    }
+
+    /**
+     * Builder of link resource request.
+     */
+    public static final class Builder implements LinkResourceRequest.Builder {
+        private IntentId intentId;
+        private Collection<Link> links;
+        private Set<ResourceRequest> resources;
+
+        /**
+         * Creates a new link resource request.
+         *
+         * @param intentId intent ID related to this request
+         * @param links a set of links for the request
+         */
+        private Builder(IntentId intentId, Collection<Link> links) {
+            this.intentId = intentId;
+            this.links = links;
+            this.resources = new HashSet<>();
+        }
+
+        /**
+         * Adds lambda request.
+         *
+         * @return self
+         */
+        @Override
+        public Builder addLambdaRequest() {
+            resources.add(new LambdaResourceRequest());
+            return this;
+        }
+
+        /**
+         * Adds bandwidth request with bandwidth value.
+         *
+         * @param bandwidth bandwidth value to be requested
+         * @return self
+         */
+        @Override
+        public Builder addBandwidthRequest(double bandwidth) {
+            resources.add(new BandwidthResourceRequest(bandwidth));
+            return this;
+        }
+
+        /**
+         * Returns link resource request.
+         *
+         * @return link resource request
+         */
+        @Override
+        public LinkResourceRequest build() {
+            return new DefaultLinkResourceRequest(intentId, links, resources);
+        }
+    }
+
+}
diff --git a/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceAllocations.java b/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceAllocations.java
index 3dce62f..a3d3e87 100644
--- a/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceAllocations.java
+++ b/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceAllocations.java
@@ -5,7 +5,7 @@
 /**
  * Representation of allocated link resources.
  */
-public interface LinkResourceAllocations {
+public interface LinkResourceAllocations extends LinkResourceRequest {
     /**
      * Returns allocated resource for the given link.
      *
diff --git a/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceRequest.java b/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceRequest.java
index 331bf83..3f32b06 100644
--- a/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceRequest.java
+++ b/core/api/src/main/java/org/onlab/onos/net/resource/LinkResourceRequest.java
@@ -1,108 +1,47 @@
 package org.onlab.onos.net.resource;
 
 import java.util.Collection;
-import java.util.HashSet;
 import java.util.Set;
 
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.intent.IntentId;
 
-import com.google.common.collect.ImmutableSet;
-
 /**
  * Representation of a request for link resource.
  */
-public final class LinkResourceRequest implements ResourceRequest {
-    // TODO: should this class be interface?
-
-    private final IntentId intentId;
-    private final Collection<Link> links;
-    private final Set<ResourceRequest> resources;
-
-    /**
-     * Creates a new link resource request with the given ID, links, and
-     * resource requests.
-     *
-     * @param intentId intent ID related to this request
-     * @param links a set of links for the request
-     * @param resources a set of resources to be requested
-     */
-    private LinkResourceRequest(IntentId intentId,
-            Collection<Link> links,
-            Set<ResourceRequest> resources) {
-        this.intentId = intentId;
-        this.links = ImmutableSet.copyOf(links);
-        this.resources = ImmutableSet.copyOf(resources);
-    }
+public interface LinkResourceRequest extends ResourceRequest {
 
     /**
      * Returns the {@link IntentId} associated with the request.
      *
      * @return the {@link IntentId} associated with the request
      */
-    IntentId intendId() {
-        return intentId;
-    }
+    IntentId intendId();
 
     /**
      * Returns the set of target links.
      *
      * @return the set of target links
      */
-    Collection<Link> links() {
-        return links;
-    }
+    Collection<Link> links();
 
     /**
      * Returns the set of resource requests.
      *
      * @return the set of resource requests
      */
-    Set<ResourceRequest> resources() {
-        return resources;
-    }
-
-    /**
-     * Returns builder of link resource request.
-     *
-     * @param intentId intent ID related to this request
-     * @param links a set of links for the request
-     * @return builder of link resource request
-     */
-    public static LinkResourceRequest.Builder builder(
-            IntentId intentId, Collection<Link> links) {
-        return new Builder(intentId, links);
-    }
+    Set<ResourceRequest> resources();
 
     /**
      * Builder of link resource request.
      */
-    public static final class Builder {
-        private IntentId intentId;
-        private Collection<Link> links;
-        private Set<ResourceRequest> resources;
-
-        /**
-         * Creates a new link resource request.
-         *
-         * @param intentId intent ID related to this request
-         * @param links a set of links for the request
-         */
-        private Builder(IntentId intentId, Collection<Link> links) {
-            this.intentId = intentId;
-            this.links = links;
-            this.resources = new HashSet<>();
-        }
-
-        /**
+    interface Builder {
+         /**
          * Adds lambda request.
          *
          * @return self
          */
-        public Builder addLambdaRequest() {
-            resources.add(new LambdaResourceRequest());
-            return this;
-        }
+        public Builder addLambdaRequest();
 
         /**
          * Adds bandwidth request with bandwidth value.
@@ -110,18 +49,13 @@
          * @param bandwidth bandwidth value to be requested
          * @return self
          */
-        public Builder addBandwidthRequest(double bandwidth) {
-            resources.add(new BandwidthResourceRequest(bandwidth));
-            return this;
-        }
+        public Builder addBandwidthRequest(double bandwidth);
 
         /**
          * Returns link resource request.
          *
          * @return link resource request
          */
-        public LinkResourceRequest build() {
-            return new LinkResourceRequest(intentId, links, resources);
-        }
+        public LinkResourceRequest build();
     }
 }