code: def _mean(x):
      if len(x) == 0:
          raise ValueError("x must have positive length")
      return float(sum(x)) / len(x)
  
file_path: catboost/contrib/python/plotly/py2/plotly/shapeannotation.py
label_desc: Use image node_id 1 for calling a global function with example usage: _mean(x) and returns: unknown