vfdev-5: We still have `[Errno 111] Connection refused`

https://github.com/pytorch/ignite/pull/1149/checks?check_run_id=795148276#step:5:802
sdesrozis: I think we have more messages. I just added a connexion check. I will inspect more precisely.
vfdev-5: @sdesrozis seems like there is `offline` mode in `Visdom`: https://github.com/facebookresearch/visdom/blob/v0.1.8.9/py/visdom/__init__.py#L413

Probably, we can use it without setup of visdom server for our tests. I let you explore that.

By the way, I could reproduce the issue by adding 
```python
def test_logger_init_hostname_port(visdom_server):
    # Explicit hostname, port
    with pytest.warns(None) as record:
        vd_logger = VisdomLogger(server=visdom_server[0], port=visdom_server[1], num_workers=0)
        assert "main" in vd_logger.vis.get_env_list()
        vd_logger.close()
        assert len(record) == 0
```
and running
```
CUDA_VISIBLE_DEVICES="" py.test -vvv tests/ignite/contrib/engines/test_common.py tests/ignite/contrib/handlers/test_visdom_logger.py 
``` 

diff --git a/ignite/contrib/handlers/visdom_logger.py b/ignite/contrib/handlers/visdom_logger.py
index a4b9a337..01e6d98c 100644
--- a/ignite/contrib/handlers/visdom_logger.py
+++ b/ignite/contrib/handlers/visdom_logger.py
@@ -454,7 +454,7 @@ class VisdomLogger(BaseLogger):
 
     """
 
-    def __init__(self, server=None, port=None, num_workers=1, **kwargs):
+    def __init__(self, server=None, port=None, num_workers=1, raise_exceptions=True, **kwargs):
         try:
             import visdom
         except ImportError:
@@ -491,11 +491,11 @@ class VisdomLogger(BaseLogger):
             password = os.environ.get("VISDOM_PASSWORD", None)
             kwargs["password"] = password
 
-        self.vis = visdom.Visdom(server=server, port=port, **kwargs)
+        self.vis = visdom.Visdom(server=server, port=port, raise_exceptions=raise_exceptions, **kwargs)
 
-        if not self.vis.check_connection():
+        if not self.vis.offline and not self.vis.check_connection():
             raise RuntimeError(
-                "Failed to connect to Visdom server at {}. " "Did you run python -m visdom.server ?".format(server)
+                "Failed to connect to Visdom server at {}. Did you run python -m visdom.server ?".format(server)
             )
 
         self.executor = _DummyExecutor()
@@ -508,8 +508,8 @@ class VisdomLogger(BaseLogger):
         self.vis.save([self.vis.env])
 
     def close(self):
-        self.vis = None
         self.executor.shutdown()
+        self.vis = None
 
     def _create_output_handler(self, *args, **kwargs):
         return OutputHandler(*args, **kwargs)

Inspect warnings from Visdom that make CI flaky
## 🐛 Bug description

LR finder catch errors from Visdom server and thus fails.

```
tests/ignite/contrib/handlers/test_lr_finder.py:202: AssertionError

------------------------------ Captured log call -------------------------------

ERROR    visdom:__init__.py:619 [Errno 111] Connection refused
ERROR    visdom:__init__.py:619 [Errno 111] Connection refused
```
https://travis-ci.org/github/pytorch/ignite/jobs/698932904#L3758

Need to inspect and fix that.


## Environment

 - PyTorch Version (e.g., 1.4):
 - Ignite Version (e.g., 0.3.0):
 - OS (e.g., Linux):
 - How you installed Ignite (`conda`, `pip`, source):
 - Python version:
 - Any other relevant information:

diff --git a/tests/ignite/contrib/conftest.py b/tests/ignite/contrib/conftest.py
index 16bfe3cc..489e0b51 100644
--- a/tests/ignite/contrib/conftest.py
+++ b/tests/ignite/contrib/conftest.py
@@ -1,21 +1,63 @@
+import random
+
 import pytest
 
 
 @pytest.fixture()
-def visdom_server():
+def visdom_offline_logfile(dirname):
 
     import os
-    import signal
-    import subprocess
-    import time
 
-    from visdom.server import download_scripts
+    log_file = os.path.join(dirname, "logs.visdom")
+    yield log_file
+
+
+vd_hostname = None
+vd_port = None
+vd_server_process = None
+
+
+@pytest.fixture()
+def visdom_server():
+    # Start Visdom server once and stop it with visdom_server_stop
+    global vd_hostname, vd_port, vd_server_process
+
+    if vd_server_process is None:
+
+        import subprocess
+        import time
+
+        from visdom import Visdom
+        from visdom.server import download_scripts
 
-    download_scripts()
+        download_scripts()
+
+        vd_hostname = "localhost"
+        vd_port = random.randint(8089, 8887)
+
+        try:
+            vis = Visdom(server=vd_hostname, port=vd_port, raise_exceptions=True)
+        except ConnectionError:
+            pass
+
+        vd_server_process = subprocess.Popen(
+            ["python", "-m", "visdom.server", "--hostname", vd_hostname, "-port", str(vd_port)]
+        )
+        time.sleep(5)
+
+        vis = Visdom(server=vd_hostname, port=vd_port)
+        assert vis.check_connection()
+        vis.close()
+
+    yield (vd_hostname, vd_port)
+
+
+@pytest.fixture()
+def visdom_server_stop():
+
+    yield None
+
+    import time
 
-    hostname = "localhost"
-    port = 8098
-    p = subprocess.Popen("visdom --hostname {} -port {}".format(hostname, port), shell=True, preexec_fn=os.setsid)
-    time.sleep(5)
-    yield (hostname, port)
-    os.killpg(os.getpgid(p.pid), signal.SIGTERM)
+    vd_server_process.kill()
+    time.sleep(2)
diff --git a/tests/ignite/contrib/engines/test_common.py b/tests/ignite/contrib/engines/test_common.py
index 8d9a8ee7..af43a826 100644
--- a/tests/ignite/contrib/engines/test_common.py
+++ b/tests/ignite/contrib/engines/test_common.py
@@ -403,10 +403,10 @@ def test_setup_tb_logging(dirname):
 
 
 @pytest.mark.skipif(sys.platform.startswith("win"), reason="Skip on Windows")
-def test_setup_visdom_logging(visdom_server):
+def test_setup_visdom_logging(visdom_offline_logfile):
     vis_logger = _test_setup_logging(
         setup_logging_fn=setup_visdom_logging,
-        kwargs_dict={"server": visdom_server[0], "port": str(visdom_server[1])},
+        kwargs_dict={"offline": True, "log_to_filename": visdom_offline_logfile},
         output_handler_cls=handlers.visdom_logger.OutputHandler,
         opt_params_handler_cls=handlers.visdom_logger.OptimizerParamsHandler,
         with_eval=False,
@@ -416,7 +416,7 @@ def test_setup_visdom_logging(visdom_server):
 
     vis_logger = _test_setup_logging(
         setup_logging_fn=setup_visdom_logging,
-        kwargs_dict={"server": visdom_server[0], "port": str(visdom_server[1])},
+        kwargs_dict={"offline": True, "log_to_filename": visdom_offline_logfile},
         output_handler_cls=handlers.visdom_logger.OutputHandler,
         opt_params_handler_cls=handlers.visdom_logger.OptimizerParamsHandler,
         with_eval=True,
diff --git a/tests/ignite/contrib/handlers/test_lr_finder.py b/tests/ignite/contrib/handlers/test_lr_finder.py
index 6e8471fa..30482302 100644
--- a/tests/ignite/contrib/handlers/test_lr_finder.py
+++ b/tests/ignite/contrib/handlers/test_lr_finder.py
@@ -199,14 +199,13 @@ def test_num_iter_is_not_enough(lr_finder, to_save, dummy_engine, dataloader):
         assert dummy_engine.state.iteration == len(dataloader)
 
 
-def test_detach_terminates(lr_finder, to_save, dummy_engine, dataloader):
+def test_detach_terminates(lr_finder, to_save, dummy_engine, dataloader, recwarn):
     with lr_finder.attach(dummy_engine, to_save, end_lr=100, diverge_th=2) as trainer_with_finder:
-        with pytest.warns(None) as record:
-            trainer_with_finder.run(dataloader)
-            assert len(record) == 0
+        trainer_with_finder.run(dataloader)
 
     dummy_engine.run(dataloader, max_epochs=3)
     assert dummy_engine.state.epoch == 3
+    assert len(recwarn) == 0
 
 
 def test_lr_suggestion(lr_finder, to_save, dummy_engine, dataloader):
diff --git a/tests/ignite/contrib/handlers/test_visdom_logger.py b/tests/ignite/contrib/handlers/test_visdom_logger.py
index 31c56413..a8bc76cd 100644
--- a/tests/ignite/contrib/handlers/test_visdom_logger.py
+++ b/tests/ignite/contrib/handlers/test_visdom_logger.py
@@ -788,11 +788,8 @@ def test_grads_scalar_handler():
 @pytest.mark.skipif(sys.platform.startswith("win"), reason="Skip on Windows")
 def test_integration_no_server():
 
-    with pytest.warns(
-        PendingDeprecationWarning, match="Visdom is eventually changing to default to raising exceptions"
-    ):
-        with pytest.raises(RuntimeError, match="Failed to connect to Visdom server"):
-            VisdomLogger()
+    with pytest.raises(ConnectionError, match="Error connecting to Visdom server"):
+        VisdomLogger()
 
 
 @pytest.mark.skipif(sys.platform.startswith("win"), reason="Skip on Windows")
@@ -800,6 +797,7 @@ def test_logger_init_hostname_port(visdom_server):
     # Explicit hostname, port
     vd_logger = VisdomLogger(server=visdom_server[0], port=visdom_server[1], num_workers=0)
     assert "main" in vd_logger.vis.get_env_list()
+    vd_logger.close()
 
 
 @pytest.mark.skipif(sys.platform.startswith("win"), reason="Skip on Windows")
@@ -811,6 +809,7 @@ def test_logger_init_env_vars(visdom_server):
     os.environ["VISDOM_PORT"] = str(visdom_server[1])
     vd_logger = VisdomLogger(server=visdom_server[0], port=visdom_server[1], num_workers=0)
     assert "main" in vd_logger.vis.get_env_list()
+    vd_logger.close()
 
 
 def _parse_content(content):
@@ -852,6 +851,7 @@ def test_integration_no_executor(visdom_server):
     x_vals, y_vals = data["x"], data["y"]
     assert all([int(x) == x_true for x, x_true in zip(x_vals, list(range(1, n_epochs * len(data) + 1)))])
     assert all([y == y_true for y, y_true in zip(y_vals, losses)])
+    vd_logger.close()
 
 
 @pytest.mark.skipif(sys.platform.startswith("win"), reason="Skip on Windows")
@@ -892,7 +892,7 @@ def test_integration_with_executor(visdom_server):
 
 
 @pytest.mark.skipif(sys.platform.startswith("win"), reason="Skip on Windows")
-def test_integration_with_executor_as_context_manager(visdom_server):
+def test_integration_with_executor_as_context_manager(visdom_server, visdom_server_stop):
 
     n_epochs = 5
     data = list(range(50))

pip install -e .
parse_log_pytest
requirements.txt
pytest
apt-get update apt-get install -y gcc pip install torch torchvision -f https://download.pytorch.org/whl/cpu/torch_stable.html -U
3.7
requirements-dev.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
absl-py==2.1.0
alembic==1.12.1
arrow==1.2.3
attrs==24.2.0
boto3==1.33.13
botocore==1.33.13
bravado==11.1.0
bravado-core==6.1.1
cached-property==1.5.2
cachetools==5.5.2
certifi @ file:///croot/certifi_1671487769961/work/certifi
charset-normalizer==3.4.1
click==7.1.2
cloudpickle==2.2.1
codecov==2.1.13
coverage==7.2.7
cycler==0.11.0
databricks-cli==0.18.0
dill==0.3.7
docker==6.1.3
docker-pycreds==0.4.0
entrypoints==0.4
exceptiongroup==1.2.2
execnet==2.0.2
Flask==1.1.4
fonttools==4.38.0
fqdn==1.5.1
funcsigs==1.0.2
furl==2.1.4
future==1.0.0
gitdb==4.0.12
GitPython==3.1.44
google-auth==2.38.0
google-auth-oauthlib==0.4.6
greenlet==3.1.1
grpcio==1.62.3
gunicorn==20.1.0
gym==0.26.2
gym-notices==0.0.8
hestia==0.6.0
humanfriendly==10.0
idna==3.10
importlib-metadata==5.2.0
importlib-resources==5.12.0
iniconfig==2.0.0
isoduration==20.11.0
itsdangerous==1.1.0
Jinja2==2.10.3
jmespath==1.0.1
joblib==1.3.2
jsonpatch==1.33
jsonpointer==3.0.0
jsonref==1.1.0
jsonschema==4.17.3
kiwisolver==1.4.5
Mako==1.2.4
Markdown==3.4.4
MarkupSafe==2.1.5
marshmallow==3.0.0rc5
matplotlib==3.5.3
mlflow==1.30.1
monotonic==1.6
msgpack==1.0.5
neptune-client==1.11.1
networkx==2.6.3
numpy==1.21.6
oauthlib==3.2.2
orderedmultidict==1.0.1
packaging==21.3
pandas==1.3.5
pathlib2==2.3.7.post1
Pillow==9.5.0
pkgutil_resolve_name==1.3.10
platformdirs==4.0.0
pluggy==1.2.0
polyaxon-client==0.6.1
polyaxon-schemas==0.6.1
polystores==0.2.5
prometheus-client==0.17.1
prometheus_flask_exporter==0.23.2
protobuf==3.20.3
psutil==7.0.0
pyasn1==0.5.1
pyasn1-modules==0.3.0
PyJWT==2.8.0
pynvml==11.5.3
pyparsing==3.1.4
pyrsistent==0.19.3
pytest==7.4.4
pytest-cov==4.1.0
pytest-xdist==3.5.0
python-dateutil==2.9.0.post0
-e git+https://github.com/pytorch/ignite.git@185320f5798f499d62591071badcc2854f267048#egg=pytorch_ignite
pytz==2022.7.1
PyYAML==6.0.1
querystring-parser==1.2.4
requests==2.31.0
requests-file==2.1.0
requests-oauthlib==2.0.0
requests-toolbelt==1.0.0
rfc3339-validator==0.1.4
rfc3986-validator==0.1.1
rhea==0.5.5
rsa==4.9
s3transfer==0.8.2
scikit-learn==1.0.2
scipy==1.7.3
sentry-sdk==2.24.1
setproctitle==1.3.3
simplejson==3.20.1
six==1.17.0
smmap==5.0.2
SQLAlchemy==1.4.54
sqlparse==0.4.4
swagger-spec-validator==3.0.3
tabulate==0.9.0
tensorboard==2.11.2
tensorboard-data-server==0.6.1
tensorboard-plugin-wit==1.8.1
tensorboardX==2.6.2.2
threadpoolctl==3.1.0
tomli==2.0.1
torch==1.13.1+cpu
torchvision==0.14.1+cpu
tornado==6.2
tqdm==4.67.1
trains==0.16.4
typing_extensions==4.7.1
uri-template==1.3.0
urllib3==1.26.20
visdom==0.2.4
wandb==0.18.7
webcolors==1.13
websocket-client==1.6.1
Werkzeug==1.0.1
zipp==3.15.0

name: ignite
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2022.12.7=py37h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=22.3.1=py37h06a4308_0
  - python=3.7.16=h7a1cb2a_0
  - readline=8.2=h5eee18b_0
  - setuptools=65.6.3=py37h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.38.4=py37h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - absl-py==2.1.0
      - alembic==1.12.1
      - arrow==1.2.3
      - attrs==24.2.0
      - boto3==1.33.13
      - botocore==1.33.13
      - bravado==11.1.0
      - bravado-core==6.1.1
      - cached-property==1.5.2
      - cachetools==5.5.2
      - charset-normalizer==3.4.1
      - click==7.1.2
      - cloudpickle==2.2.1
      - codecov==2.1.13
      - coverage==7.2.7
      - cycler==0.11.0
      - databricks-cli==0.18.0
      - dill==0.3.7
      - docker==6.1.3
      - docker-pycreds==0.4.0
      - entrypoints==0.4
      - exceptiongroup==1.2.2
      - execnet==2.0.2
      - flask==1.1.4
      - fonttools==4.38.0
      - fqdn==1.5.1
      - funcsigs==1.0.2
      - furl==2.1.4
      - future==1.0.0
      - gitdb==4.0.12
      - gitpython==3.1.44
      - google-auth==2.38.0
      - google-auth-oauthlib==0.4.6
      - greenlet==3.1.1
      - grpcio==1.62.3
      - gunicorn==20.1.0
      - gym==0.26.2
      - gym-notices==0.0.8
      - hestia==0.6.0
      - humanfriendly==10.0
      - idna==3.10
      - importlib-metadata==5.2.0
      - importlib-resources==5.12.0
      - iniconfig==2.0.0
      - isoduration==20.11.0
      - itsdangerous==1.1.0
      - jinja2==2.10.3
      - jmespath==1.0.1
      - joblib==1.3.2
      - jsonpatch==1.33
      - jsonpointer==3.0.0
      - jsonref==1.1.0
      - jsonschema==4.17.3
      - kiwisolver==1.4.5
      - mako==1.2.4
      - markdown==3.4.4
      - markupsafe==2.1.5
      - marshmallow==3.0.0rc5
      - matplotlib==3.5.3
      - mlflow==1.30.1
      - monotonic==1.6
      - msgpack==1.0.5
      - neptune-client==1.11.1
      - networkx==2.6.3
      - numpy==1.21.6
      - oauthlib==3.2.2
      - orderedmultidict==1.0.1
      - packaging==21.3
      - pandas==1.3.5
      - pathlib2==2.3.7.post1
      - pillow==9.5.0
      - pkgutil-resolve-name==1.3.10
      - platformdirs==4.0.0
      - pluggy==1.2.0
      - polyaxon-client==0.6.1
      - polyaxon-schemas==0.6.1
      - polystores==0.2.5
      - prometheus-client==0.17.1
      - prometheus-flask-exporter==0.23.2
      - protobuf==3.20.3
      - psutil==7.0.0
      - pyasn1==0.5.1
      - pyasn1-modules==0.3.0
      - pyjwt==2.8.0
      - pynvml==11.5.3
      - pyparsing==3.1.4
      - pyrsistent==0.19.3
      - pytest==7.4.4
      - pytest-cov==4.1.0
      - pytest-xdist==3.5.0
      - python-dateutil==2.9.0.post0
      - pytorch-ignite==0.5.0
      - pytz==2022.7.1
      - pyyaml==6.0.1
      - querystring-parser==1.2.4
      - requests==2.31.0
      - requests-file==2.1.0
      - requests-oauthlib==2.0.0
      - requests-toolbelt==1.0.0
      - rfc3339-validator==0.1.4
      - rfc3986-validator==0.1.1
      - rhea==0.5.5
      - rsa==4.9
      - s3transfer==0.8.2
      - scikit-learn==1.0.2
      - scipy==1.7.3
      - sentry-sdk==2.24.1
      - setproctitle==1.3.3
      - simplejson==3.20.1
      - six==1.17.0
      - smmap==5.0.2
      - sqlalchemy==1.4.54
      - sqlparse==0.4.4
      - swagger-spec-validator==3.0.3
      - tabulate==0.9.0
      - tensorboard==2.11.2
      - tensorboard-data-server==0.6.1
      - tensorboard-plugin-wit==1.8.1
      - tensorboardx==2.6.2.2
      - threadpoolctl==3.1.0
      - tomli==2.0.1
      - torch==1.13.1+cpu
      - torchvision==0.14.1+cpu
      - tornado==6.2
      - tqdm==4.67.1
      - trains==0.16.4
      - typing-extensions==4.7.1
      - uri-template==1.3.0
      - urllib3==1.26.20
      - visdom==0.2.4
      - wandb==0.18.7
      - webcolors==1.13
      - websocket-client==1.6.1
      - werkzeug==1.0.1
      - zipp==3.15.0
prefix: /opt/conda/envs/ignite

tests/ignite/contrib/engines/test_common.py::test_setup_visdom_logging tests/ignite/contrib/handlers/test_visdom_logger.py::test_integration_no_server
tests/ignite/contrib/engines/test_common.py::test_setup_plx_logging tests/ignite/contrib/engines/test_common.py::test_setup_neptune_logging
tests/ignite/contrib/engines/test_common.py::test_asserts_setup_common_training_handlers tests/ignite/contrib/engines/test_common.py::test_no_warning_with_train_sampler tests/ignite/contrib/engines/test_common.py::test_setup_common_training_handlers tests/ignite/contrib/engines/test_common.py::test_setup_common_training_handlers_using_save_handler tests/ignite/contrib/engines/test_common.py::test_save_best_model_by_val_score tests/ignite/contrib/engines/test_common.py::test_gen_save_best_models_by_val_score tests/ignite/contrib/engines/test_common.py::test_add_early_stopping_by_val_score tests/ignite/contrib/engines/test_common.py::test_deprecated_setup_any_logging tests/ignite/contrib/engines/test_common.py::test__setup_logging_wrong_args tests/ignite/contrib/engines/test_common.py::test_setup_tb_logging tests/ignite/contrib/engines/test_common.py::test_setup_mlflow_logging tests/ignite/contrib/engines/test_common.py::test_setup_wandb_logging tests/ignite/contrib/engines/test_common.py::test_setup_trains_logging tests/ignite/contrib/engines/test_common.py::test_distrib_cpu tests/ignite/contrib/handlers/test_lr_finder.py::test_attach_incorrect_input_args tests/ignite/contrib/handlers/test_lr_finder.py::test_attach_without_with tests/ignite/contrib/handlers/test_lr_finder.py::test_with_attach tests/ignite/contrib/handlers/test_lr_finder.py::test_model_optimizer_reset tests/ignite/contrib/handlers/test_lr_finder.py::test_lr_policy tests/ignite/contrib/handlers/test_lr_finder.py::test_num_iter_is_none tests/ignite/contrib/handlers/test_lr_finder.py::test_num_iter_is_enough tests/ignite/contrib/handlers/test_lr_finder.py::test_num_iter_is_not_enough tests/ignite/contrib/handlers/test_lr_finder.py::test_detach_terminates tests/ignite/contrib/handlers/test_lr_finder.py::test_lr_suggestion tests/ignite/contrib/handlers/test_lr_finder.py::test_plot tests/ignite/contrib/handlers/test_lr_finder.py::test_no_matplotlib tests/ignite/contrib/handlers/test_visdom_logger.py::test_optimizer_params_handler_wrong_setup tests/ignite/contrib/handlers/test_visdom_logger.py::test_optimizer_params tests/ignite/contrib/handlers/test_visdom_logger.py::test_output_handler_with_wrong_logger_type tests/ignite/contrib/handlers/test_visdom_logger.py::test_output_handler_output_transform tests/ignite/contrib/handlers/test_visdom_logger.py::test_output_handler_metric_names tests/ignite/contrib/handlers/test_visdom_logger.py::test_output_handler_both tests/ignite/contrib/handlers/test_visdom_logger.py::test_output_handler_with_wrong_global_step_transform_output tests/ignite/contrib/handlers/test_visdom_logger.py::test_output_handler_with_global_step_transform tests/ignite/contrib/handlers/test_visdom_logger.py::test_output_handler_with_global_step_from_engine tests/ignite/contrib/handlers/test_visdom_logger.py::test_weights_scalar_handler_wrong_setup tests/ignite/contrib/handlers/test_visdom_logger.py::test_weights_scalar_handler tests/ignite/contrib/handlers/test_visdom_logger.py::test_weights_scalar_handler_custom_reduction tests/ignite/contrib/handlers/test_visdom_logger.py::test_grads_scalar_handler_wrong_setup tests/ignite/contrib/handlers/test_visdom_logger.py::test_grads_scalar_handler tests/ignite/contrib/handlers/test_visdom_logger.py::test_no_visdom
ignite/contrib/handlers/visdom_logger.py
ignite/contrib/handlers/visdom_logger.py