code: def to_refs(value):
      
      from mongoframes.frames import Frame, SubFrame
  
      # Frame
      if isinstance(value, Frame):
          return value._id
  
      # SubFrame
      elif isinstance(value, SubFrame):
          return to_refs(value._document)
  
      # Lists
      elif isinstance(value, (list, tuple)):
          return [to_refs(v) for v in value]
  
      # Dictionaries
      elif isinstance(value, dict):
          return {k: to_refs(v) for k, v in value.items()}
  
      return value
docs: Convert all Frame instances within the given value to Ids