code: def ensure_geo_reference(origin):
      
  
      if isinstance(origin, Geo_reference):
          geo_ref = origin
      elif origin is None:
          geo_ref = None
      else:
          geo_ref = apply(Geo_reference, origin)
  
      return geo_ref
docs: Given a list/tuple of zone, xllcorner and yllcorner of a geo-ref object,
      return a geo ref object.
  
      If the origin is None, return None, so calling this function doesn't
      effect code logic