class_docstr: NWCSAF PPS&MSG NetCDF reader.
docstr: Return the start time of the object.
docstr_tok: ["Return","the","start","time","of","the","object","."]
code: def start_time(self):
      """Return the start time of the object."""
      try:
          return read_nwcsaf_time(self.nc.attrs["nominal_product_time"])
      except KeyError:
          return read_nwcsaf_time(self.nc.attrs["time_coverage_start"])
  
imports: import functools
  import logging
  import os
  from contextlib import suppress
  from datetime import datetime
  import dask.array
  import numpy
  import xarray
  from pyproj import CRS
  from pyresample.geometry import AreaDefinition
  from satpy.readers.file_handlers import BaseFileHandler
  from satpy.readers.utils import unzip_file
  from satpy.utils import get_chunk_size_limit
label_desc: Use image node_id 17 for calling the NcNWCSAF obj's underlying member method code with example usage: obj.start_time() and returns: read_nwcsaf_time, read_nwcsaf_time