code: def flatten_vertex_structure_adder(
      nodes: List,
      nodes_hits: Set[str],
      vertex: Vertex,
      id_col: str = "id",
      label_col: str = "label",
  ) -> Optional[dict]:
      """
      Return item when added as fresh
      """
      if vertex.id in nodes_hits:
          return None
      d = flatten_vertex_structure(vertex, id_col, label_col)
      nodes.append(d)
      nodes_hits.add(vertex.id)
      return d
  
imports: from typing import Any, Callable, Iterable, List, Optional, Set, Union, TYPE_CHECKING
  import os, pandas
  from .Plottable import Plottable
  from .util import setup_logger
label_desc: Use image node_id 12 for calling a global function with example usage: flatten_vertex_structure_adder(nodes, nodes_hits, vertex, id_col, label_col) and returns: d, None