code: def _model_idx(model_name):
      pref = model_name[
          :3
      ]  # use first three letters are prefix for the index
      if pref not in _MODELS:
          _MODELS[pref] = {}
      _models = _MODELS[pref]
      if model_name not in _models:
          _models[model_name] = f"{pref}{len(_models)}"
      return _models[model_name]
  
imports: import json
  import os
  from math import ceil, floor
  from pathlib import Path
  import matplotlib.pyplot
  import numpy
  import pandas
  import seaborn
  from IPython.display import display_html
  from matplotlib.ticker import FixedLocator
  from vissl.utils.io import load_file, save_file
label_desc: Use image node_id 7 for calling a global function with example usage: _model_idx(model_name) and returns: _models