class_docstr: Test the AMI L1b reader.
class_docstr_tok: ["Test","the","AMI","L1b","reader","."]
docstr: Test that filenames are grouped properly.
docstr_tok: ["Test","that","filenames","are","grouped","properly","."]
code: def test_filename_grouping(self):
      """Test that filenames are grouped properly."""
      from satpy.readers import group_files
  
      filenames = [
          "gk2a_ami_le1b_ir087_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_ir096_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_ir105_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_ir112_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_ir123_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_ir133_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_nr013_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_nr016_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_sw038_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_vi004_fd010ge_201909300300.nc",
          "gk2a_ami_le1b_vi005_fd010ge_201909300300.nc",
          "gk2a_ami_le1b_vi006_fd005ge_201909300300.nc",
          "gk2a_ami_le1b_vi008_fd010ge_201909300300.nc",
          "gk2a_ami_le1b_wv063_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_wv069_fd020ge_201909300300.nc",
          "gk2a_ami_le1b_wv073_fd020ge_201909300300.nc",
      ]
      groups = group_files(filenames, reader="ami_l1b")
      assert len(groups) == 1
      assert len(groups[0]["ami_l1b"]) == 16
  
imports: import unittest
  from unittest import mock
  import dask.array
  import numpy
  import xarray
  from pytest import approx, raises
label_desc: Use image node_id 2 for calling the TestAMIL1bNetCDF obj's underlying member method code with example usage: obj.test_filename_grouping() without return types