class_docstr: Testcase for dataset metadata.
class_docstr_tok: ["Testcase","for","dataset","metadata","."]
docstr: Set channel ID.
code: def channel_id(self, request):
      """Set channel ID."""
      return request.param
  
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 TestMetadata obj's underlying member method code with example usage: obj.channel_id(request) and returns: request