preparing test

test/cases/class_def/class_derived.tst

@@ -1,10 +1,28 @@
 class Foo < Object
+  int field = 3
+  int func()
+    return self.field
+  end
   ofthen(3 , var)
 end
 -- -- --
 s(:expressions,
   s(:class, :Foo,
     s(:derives, :Object),
+    s(:name, :int),
+    s(:assign,
+      s(:name, :field),
+      s(:int, 3)),
+    s(:function, :int,
+      s(:name, :func),
+      s(:parameters),
+      s(:expressions,
+        s(:return,
+          s(:field_access,
+            s(:receiver,
+              s(:name, :self)),
+            s(:field,
+              s(:name, :field)))))),
     s(:call,
       s(:name, :ofthen),
       s(:arguments,