code: def new_trace(self):
      self.top += 1
      yield self.top
      self.top -= 1
  
imports: import warnings
  from contextlib import contextmanager
  from collections import defaultdict
  from .util import subvals, toposort
  from .wrap_util import wraps
label_desc: Use image node_id 2 for calling the TraceStack obj's underlying member method code with example usage: obj.new_trace() without return types