text: import pyeccodes.accessors as _
  
  
  def load(h):
  
      h.alias('mars.origin', 'centre')
      h.add(_.G1fcperiod('forecastperiod', _.Get('P1'), _.Get('P2'), _.Get('timeRangeIndicator'), _.Get('indicatorOfUnitOfTimeRange')))
      h.alias('mars.fcperiod', 'forecastperiod')
      h.unalias('mars.step')
      h.alias('mars.method', 'methodNumber')
  
      if (h.get_s('class') == "od"):
          h.alias('mars.system', 'systemNumber')
  
  