class_docstr: VIIRS L1B File Reader.
class_docstr_tok: ["VIIRS","L1B","File","Reader","."]
code: def _get_dataset_file_units(self, dataset_id, ds_info, var_path):
      file_units = ds_info.get("file_units")
      if file_units is None:
          file_units = self.get(var_path + "/attr/units")
          # they were almost completely CF compliant...
          if file_units == "none":
              file_units = "1"
  
      if (
          dataset_id.get("calibration") == "radiance"
          and ds_info["units"] == "W m-2 um-1 sr-1"
      ):
          rad_units_path = var_path + "/attr/radiance_units"
          if rad_units_path in self:
              if file_units is None:
                  file_units = self[var_path + "/attr/radiance_units"]
              if file_units == "Watts/meter^2/steradian/micrometer":
                  file_units = "W m-2 um-1 sr-1"
      elif ds_info.get("units") == "%" and file_units is None:
          # v1.1 and above of level 1 processing removed 'units' attribute
          # for all reflectance channels
          file_units = "1"
  
      return file_units
  
imports: import logging
  from datetime import datetime
  import numpy
  from satpy.readers.netcdf_utils import NetCDF4FileHandler
label_desc: Use image node_id 10 for calling the VIIRSL1BFileHandler obj's underlying member method code with example usage: obj._get_dataset_file_units(dataset_id, ds_info, var_path) and returns: file_units