Minor code refinements.

Author: chrfrantz

src/main/java/org/nlogo/extensions/dbscan/DBSCANExtension.java

@@ -11,6 +11,7 @@
 import org.nlogo.api.AgentSet;
 import org.nlogo.api.Argument;
 import org.nlogo.api.Context;
+import org.nlogo.api.DefaultClassManager;
 import org.nlogo.api.DefaultReporter;
 import org.nlogo.api.ExtensionException;
 import org.nlogo.api.LogoException;
@@ -26,7 +27,7 @@
  * @author Christopher Frantz <[email protected]>
  *
  */
-public class DBSCANExtension extends org.nlogo.api.DefaultClassManager {
+public class DBSCANExtension extends DefaultClassManager {
 
 	@Override
 	public void load(PrimitiveManager primitiveManager) throws ExtensionException {

src/test/java/org/nlogo/extensions/dbscan/TestNetLogoDBSCAN.java

@@ -47,7 +47,7 @@ public void testClusteringInExistingNetLogoModelFromJava() {
 			fail("Problems when opening NetLogo model file: " + e1.getMessage());
 		}
 
-		World world = ws.world;
+		World world = ws.world();
 
 		LogoListBuilder b = new LogoListBuilder();
 		AgentSet breed = world.getBreed(AGENTS);