code: def naive_error(
      y_past: ma.masked_array,  # type: ignore
      seasonality: int,
  ) -> npt.NDArray[np.float32]:
      error = np.abs(
          y_past[:, seasonality:] - y_past[:, :-seasonality]
      ).mean(1)
      return ma.getdata(error)
  
file_path: gluonts/src/gluonts/nursery/tsbench/src/tsbench/forecasts/metrics.py
imports: import math
  import numpy
  import numpy.typing
  from numpy import ma
  from .quantile import QuantileForecasts
label_desc: Use image node_id 5 for calling a global function with example usage: naive_error(y_past, seasonality) and returns: ma