class_docstr: File handler for NC seviri files.
  
  **Calibration**
  
  See :mod:`satpy.readers.seviri_base`. Note that there is only one set of
  calibration coefficients available in the netCDF files and therefore there
  is no `calib_mode` argument.
  
  **Metadata**
  
  See :mod:`satpy.readers.seviri_base`.
docstr: Get repeat cycle duration from the metadata.
code: def _repeat_cycle_duration(self):
      """Get repeat cycle duration from the metadata."""
      if self.nc.attrs["nominal_image_scanning"] == "T":
          return 15
      elif self.nc.attrs["reduced_scanning"] == "T":
          return 5
  
imports: import datetime
  import logging
  from datetime import timedelta
  import numpy
  from satpy._compat import cached_property
  from satpy.readers._geos_area import get_area_definition, get_geos_area_naming
  from satpy.readers.eum_base import get_service_mode
  from satpy.readers.file_handlers import BaseFileHandler, open_dataset
  from satpy.readers.seviri_base import CHANNEL_NAMES, SATNUM, NoValidOrbitParams, OrbitPolynomialFinder, SEVIRICalibrationHandler, add_scanline_acq_time, get_cds_time, get_satpos, mask_bad_quality, round_nom_time
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 2 for calling the NCSEVIRIFileHandler obj's underlying member method code with example usage: obj._repeat_cycle_duration() and returns: int, int