code: def load_at2_file(cls, filename):
          
          with open(filename) as fp:
              next(fp)
              description = next(fp).strip()
              next(fp)
              parts = next(fp).split()
              time_step = float(parts[1])
  
              accels = [float(p) for l in fp for p in l.split()]
  
          return cls(filename, description, time_step, accels)
docs: Read an AT2 formatted time series.
  
          Parameters
          ----------
          filename: str
              Filename to open.