Add basic unit tests for obj.js.

src/obj.js

@@ -8,8 +8,7 @@ var Name = (function NameClosure() {
     this.name = name;
   }
 
-  Name.prototype = {
-  };
+  Name.prototype = {};
 
   return Name;
 })();
@@ -19,9 +18,7 @@ var Cmd = (function CmdClosure() {
     this.cmd = cmd;
   }
 
-  Cmd.prototype = {
-  };
-
+  Cmd.prototype = {};
 
   var cmdCache = {};
 
@@ -80,8 +77,7 @@ var Ref = (function RefClosure() {
     this.gen = gen;
   }
 
-  Ref.prototype = {
-  };
+  Ref.prototype = {};
 
   return Ref;
 })();