small cleanup and test from user contribution/question

Author: scotthernandez

src/main/com/mongodb/DBCollection.java

@@ -19,12 +19,10 @@
 package com.mongodb;
 
 // Mongo
-import org.bson.types.*;
-import com.mongodb.util.*;
-
-// Java
 import java.util.*;
 
+import org.bson.types.ObjectId;
+
 /** This class provides a skeleton implementation of a database collection.  
  * <p>A typical invocation sequence is thus
  * <blockquote><pre>
@@ -556,9 +554,7 @@ public final DBObject findOne( DBObject o )
      */
     public final DBObject findOne( DBObject o, DBObject fields ) {
         Iterator<DBObject> i = __find( o , fields , 0 , -1 , 0, getOptions() );
-        if ( i == null || ! i.hasNext() )
-            return null;
-        return i.next();
+        return i == null ? null : i.next();
     }
 
     /**

src/test/com/mongodb/DBCollectionTest.java

@@ -16,12 +16,12 @@
 
 package com.mongodb;
 
-import java.io.*;
-import java.util.*;
+import java.io.IOException;
+import java.util.List;
 
-import org.testng.annotations.*;
+import org.testng.annotations.Test;
 
-import com.mongodb.util.*;
+import com.mongodb.util.TestCase;
 
 public class DBCollectionTest extends TestCase {
 
@@ -53,6 +53,12 @@ public void testFindOne() {
         DBObject obj = c.findOne();
         assertEquals(obj, null);
 
+        obj = c.findOne(null);
+        assertEquals(obj, null);
+
+        obj = c.findOne(null, null);
+        assertEquals(obj, null);
+
         DBObject inserted = BasicDBObjectBuilder.start().add("x",1).add("y",2).get();
         c.insert(inserted);
         c.insert(BasicDBObjectBuilder.start().add("_id", 123).add("x",2).add("z",2).get());