old_contents: 
  class Frame(object):
      def __init__(self, bytecode, f_back):
          self.bytecode = bytecode
          self.f_back = f_back
          if bytecode.module is not None: # for tests
              self.globals_w = bytecode.module.functions
          self.locals_w = [None] * len(bytecode.varnames)
          self.stack_w = [None] * bytecode.stack_depth
          self.resume_stack = [0] * bytecode.resume_stack_depth
          self.resume_stack_depth = 0
          self.pos = 0
  
      def populate_args(self, args_w):
          for i in range(len(args_w)):
              self.locals_w[i] = args_w[i]
  
      def push(self, w_val):
          self.stack_w[self.pos] = w_val
          self.pos += 1
  
      def pop(self):
          new_pos = self.pos - 1
          w_res = self.stack_w[new_pos]
          assert new_pos >= 0
          self.pos = new_pos
          return w_res
  
      def peek(self):
          return self.stack_w[self.pos - 1]
  
      def store_var(self, index):
          self.locals_w[index] = self.pop()
  
new_contents: 
  from nolang.objects.root import W_Root
  
  class Frame(W_Root):
      def __init__(self, bytecode, f_back):
          self.bytecode = bytecode
          self.f_back = f_back
          if bytecode.module is not None: # for tests
              self.globals_w = bytecode.module.functions
          self.locals_w = [None] * len(bytecode.varnames)
          self.stack_w = [None] * bytecode.stack_depth
          self.resume_stack = [0] * bytecode.resume_stack_depth
          self.resume_stack_depth = 0
          self.pos = 0
  
      def populate_args(self, args_w):
          for i in range(len(args_w)):
              self.locals_w[i] = args_w[i]
  
      def push(self, w_val):
          self.stack_w[self.pos] = w_val
          self.pos += 1
  
      def pop(self):
          new_pos = self.pos - 1
          w_res = self.stack_w[new_pos]
          assert new_pos >= 0
          self.pos = new_pos
          return w_res
  
      def peek(self):
          return self.stack_w[self.pos - 1]
  
      def store_var(self, index):
          self.locals_w[index] = self.pop()
  
subject: fix rpython