code: def dump_param_targets(self) -> t.Set[str]:
      rv = set()
      node: t.Optional["Symbols"] = self
  
      while node is not None:
          for target, (instr, _) in self.loads.items():
              if instr == VAR_LOAD_PARAMETER:
                  rv.add(target)
  
          node = node.parent
  
      return rv
  
imports: import typing
  from .None import nodes
  from .visitor import NodeVisitor
label_desc: Use image node_id 13 for calling the Symbols obj's underlying member method code with example usage: obj.dump_param_targets() and returns: rv