Add some code to prevent NPEs

cluster/src/main/scala/com/linkedin/norbert/cluster/Node.scala

@@ -15,15 +15,14 @@
  */
 package com.linkedin.norbert.cluster
 
-import scala.reflect.BeanProperty
 import com.google.protobuf.InvalidProtocolBufferException
 import com.linkedin.norbert.protos.NorbertProtos
 
 /**
  * The <code>Node</code> companion object. Provides factory methods and implicits.
  */
 object Node {
-  
+
   /**
    * Creates a <code>Node</code> instance with no partitions assigned to it.
    *
@@ -86,7 +85,7 @@ object Node {
 final case class Node(id: Int, url: String, partitions: Set[Int], available: Boolean) {
   if (url == null) throw new NullPointerException("url must not be null")
   if (partitions == null) throw new NullPointerException("partitions must not be null")
-  
+
   override def hashCode = id.hashCode
 
   override def equals(other: Any) = other match {

java-cluster/src/main/scala/com/linkedin/norbert/cluster/javaapi/Implicits.scala

@@ -1,3 +1,18 @@
+/*
+ * Copyright 2009-2010 LinkedIn, Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
 package com.linkedin.norbert.cluster.javaapi
 
 import com.linkedin.norbert.cluster.javaapi.{Node => JNode}
@@ -6,11 +21,13 @@ import com.linkedin.norbert.cluster.{Node => SNode}
 object Implicits {
   import collection.jcl.Conversions._
 
-  implicit def scalaNodeToJavaNode(node: SNode): JNode = JavaNode(node)
+  implicit def scalaNodeToJavaNode(node: SNode): JNode = {
+    if (node == null) null else JavaNode(node)
+  }
 
   implicit def javaNodeToScalaNode(node: JNode): SNode = {
-    val s = node.getPartitions.asInstanceOf[java.util.Set[Int]].foldLeft(Set[Int]()) { (set, id) => set + id }
-    SNode(node.getId, node.getUrl, s, node.isAvailable)
+    if (node == null) null else SNode(node.getId, node.getUrl,
+      node.getPartitions.asInstanceOf[java.util.Set[Int]].foldLeft(Set[Int]()) { (set, id) => set + id }, node.isAvailable)
   }
 
   implicit def scalaNodeSetToJavaNodeSet(nodes: Set[SNode]): java.util.Set[JNode] = {