class_docstr: Test the file handler.
class_docstr_tok: ["Test","the","file","handler","."]
docstr: Set up the tests.
code: def setUp(self, xr_):
      """Set up the tests."""
      from satpy.readers.goes_imager_nc import (
          CALIB_COEFS,
          GOESNCFileHandler,
      )
  
      self.coefs = CALIB_COEFS["GOES-15"]
      self.all_coefs = CALIB_COEFS
      self.channels = sorted(self.coefs.keys())
      self.ir_channels = sorted(
          [ch for ch in self.channels if not is_vis_channel(ch)]
      )
      self.vis_channels = sorted(
          [ch for ch in self.channels if is_vis_channel(ch)]
      )
  
      # Mock file access to return a fake dataset. Choose a medium count value
      # (100) to avoid elements being masked due to invalid
      # radiance/reflectance/BT
      nrows = ncols = 300
      self.counts = (
          100 * 32 * np.ones((1, nrows, ncols))
      )  # emulate 10-bit
      self.lon = np.zeros((nrows, ncols))  # Dummy
      self.lat = np.repeat(
          np.linspace(-150, 150, nrows), ncols
      ).reshape(
          nrows, ncols
      )  # Includes invalid values to be masked
  
      xr_.open_dataset.return_value = xr.Dataset(
          {
              "data": xr.DataArray(
                  data=self.counts, dims=("time", "yc", "xc")
              ),
              "lon": xr.DataArray(data=self.lon, dims=("yc", "xc")),
              "lat": xr.DataArray(data=self.lat, dims=("yc", "xc")),
              "time": xr.DataArray(
                  data=np.array([0], dtype="datetime64[ns]"),
                  dims=("time",),
              ),
              "bands": xr.DataArray(data=np.array([1])),
          },
          attrs={"Satellite Sensor": "G-15"},
      )
  
      # Instantiate reader using the mocked open_dataset() method
      self.reader = GOESNCFileHandler(
          filename="dummy", filename_info={}, filetype_info={}
      )
  
imports: import datetime
  import unittest
  from unittest import mock
  import numpy
  import pytest
  import xarray
  from pyresample.geometry import AreaDefinition
  from satpy.readers.goes_imager_nc import is_vis_channel
  from satpy.tests.utils import make_dataid
label_desc: Use image node_id 1 for calling the GOESNCFileHandlerTest obj's underlying member method code with example usage: obj.setUp(xr_) without return types