Framing a null element return null.

https://github.com/tinkerpop/frames/issues/58

Author: BrynCooke

CHANGELOG.textile

@@ -15,13 +15,14 @@ h3. Version 2.4.0 (NOT OFFICIALLY RELEASED YET)
 </dependency>
 ```
 
+* Framing a null element returns null   
 * Fixed NPE when enum property type set to null
 * Inheritance/Poymorphism support
 * Factory/Module support
 * Fix detection of parameterized return types
-* AdjacencyAnnotationHandler operates against the graph being framed rather than the base graph
-* FramedTransactionalGraph support
-* Support subclassing in FramedGraphFactory
+* @AdjacencyAnnotationHandler@ operates against the graph being framed rather than the base graph
+* @FramedTransactionalGraph@ support
+* Support subclassing in @FramedGraphFactory@
 ==<hr/>==
 
 h3. Version 2.3.2 (NOT OFFICIALLY RELEASED YET)

src/main/java/com/tinkerpop/frames/FramedGraph.java

@@ -86,6 +86,10 @@ public FramedGraph(final T baseGraph) {
 	 *         perspective of the annotate interface
 	 */
 	public <F> F frame(final Vertex vertex, final Class<F> kind) {
+		if(vertex == null) {
+			return null;
+		}
+		
 		Collection<Class<?>> resolvedTypes = new HashSet<Class<?>>();
 		resolvedTypes.add(VertexFrame.class);
 		resolvedTypes.add(kind);
@@ -115,6 +119,11 @@ public <F> F frame(final Vertex vertex, final Class<F> kind) {
 	 */
 	public <F> F frame(final Edge edge, final Direction direction,
 			final Class<F> kind) {
+		
+		if(edge == null) {
+			return null;
+		}
+		
 		Collection<Class<?>> resolvedTypes = new HashSet<Class<?>>();
 		resolvedTypes.add(EdgeFrame.class);
 		resolvedTypes.add(kind);

src/test/java/com/tinkerpop/frames/FramedGraphTest.java

@@ -3,6 +3,8 @@
 import java.lang.reflect.Method;
 import java.util.HashSet;
 
+import junit.framework.Assert;
+
 import com.tinkerpop.blueprints.Direction;
 import com.tinkerpop.blueprints.Edge;
 import com.tinkerpop.blueprints.EdgeTestSuite;
@@ -97,6 +99,21 @@ public void testCreateFrame() {
 
     }
 
+    public void testCreateFrameForNonexistantElements() {
+        Graph graph = new TinkerGraph();
+        FramedGraph<Graph> framedGraph = new FramedGraphFactory().create(graph);
+        Person vertex = framedGraph.getVertex(-1, Person.class);
+        Assert.assertNull(vertex);
+        vertex = framedGraph.frame(null, Direction.IN, Person.class);
+        Assert.assertNull(vertex);
+        
+        Knows edge = framedGraph.getEdge(-1, Direction.IN, Knows.class);
+        Assert.assertNull(edge);
+        edge = framedGraph.frame(null, Direction.IN, Knows.class);
+        Assert.assertNull(edge);
+        
+    }
+    
 
     public void testVertexTestSuite() throws Exception {
         this.stopWatch();