code: def test_explicit_description(self):
      output = mock.create_autospec(output_lib.Output)
      w = writer_lib.Writer(output)
      w.add_scalar("foo", 42.0, 12, description="fooful")
      output.emit_scalar.assert_called_once()
      _, kwargs = output.emit_scalar.call_args
      self.assertEqual("fooful", kwargs["description"])
  
imports: import time
  from unittest import mock
  import numpy
  from tensorboard.compat.proto import summary_pb2
  from tensorboard.summary import _output
  from tensorboard.summary import _writer
  from tensorboard.summary import _test_util
  from tensorboard.util import tensor_util
  from tensorboard import test
label_desc: Use image node_id 8 for calling the WriterAddScalarTest obj's underlying member method code with example usage: obj.test_explicit_description() without return types