code: def linear_space(
      F, backcast_length: int, forecast_length: int, fwd_looking: bool
  ):
      if fwd_looking:
          return F.arange(0, forecast_length) / forecast_length
      else:
          return F.arange(-backcast_length, 0) / backcast_length
  
imports: from typing import List, Optional
  import mxnet
  import numpy
  from gluonts.core.component import validated
  from gluonts.mx import Tensor
  from gluonts.mx.block.scaler import MeanScaler, NOPScaler
  from gluonts.time_feature import get_seasonality
label_desc: Use image node_id 1 for calling a global function with example usage: linear_space(F, backcast_length, forecast_length, fwd_looking) and returns: unknown, unknown