code: def render_head(self, r: "Renderer") -> str:
      return self.s
  
imports: from hail import ir
  import abc
  from typing import Sequence, MutableSequence, List, Set, Dict, Optional
  from collections import namedtuple
label_desc: Use image node_id 2 for calling the RenderableStr obj's underlying member method code with example usage: obj.render_head(r) and returns: self