code: def symmetric_absolute_percentage_error(
      data: Dict[str, np.ndarray], forecast_type: str
  ) -> np.ndarray:
      return (
          2
          * absolute_error(data, forecast_type)
          / (absolute_label(data) + np.abs(data[forecast_type]))
      )
  
file_path: gluonts/src/gluonts/ev/stats.py
imports: from typing import Dict
  import numpy
label_desc: Use image node_id 9 for calling a global function with example usage: symmetric_absolute_percentage_error(data, forecast_type) and returns: unknown