We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
DOC: private methods used in cookbook recipe
### Bug report

**Bug summary**

in #2567, `doc/source/cookbook/render_two_fields_tf.py` was added to the cookbook
On the two following lines, the private method `_get_field_info` is used
https://github.com/yt-project/yt/blob/ef08989d8222e7172751d17009959102db05dd20/doc/source/cookbook/render_two_fields_tf.py#L15
https://github.com/yt-project/yt/blob/ef08989d8222e7172751d17009959102db05dd20/doc/source/cookbook/render_two_fields_tf.py#L30

This should be refactored to avoid showing private elements
@zingale, do you know how we could do this ?

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `doc/source/cookbook/render_two_fields_tf.py`
Content:
```
1 import numpy as np
2 
3 import yt
4 from yt.visualization.volume_rendering.api import Scene, create_volume_source
5 
6 ds = yt.load("IsolatedGalaxy/galaxy0030/galaxy0030")
7 
8 # create a scene and add volume sources to it
9 
10 sc = Scene()
11 
12 # Add density
13 
14 field = "density"
15 ds._get_field_info(field).take_log = True
16 
17 vol = create_volume_source(ds, field=field)
18 vol.use_ghost_zones = True
19 
20 tf = yt.ColorTransferFunction([-28, -25])
21 tf.clear()
22 tf.add_layers(4, 0.02, alpha=np.logspace(-3, -1, 4), colormap="winter")
23 
24 vol.set_transfer_function(tf)
25 sc.add_source(vol)
26 
27 # Add temperature
28 
29 field = "temperature"
30 ds._get_field_info(field).take_log = True
31 
32 vol2 = create_volume_source(ds, field=field)
33 vol2.use_ghost_zones = True
34 
35 tf = yt.ColorTransferFunction([4.5, 7.5])
36 tf.clear()
37 tf.add_layers(4, 0.02, alpha=np.logspace(-0.2, 0, 4), colormap="autumn")
38 
39 vol2.set_transfer_function(tf)
40 sc.add_source(vol2)
41 
42 # setup the camera
43 
44 cam = sc.add_camera(ds, lens_type="perspective")
45 cam.resolution = (1600, 900)
46 cam.zoom(20.0)
47 
48 # Render the image.
49 
50 sc.render()
51 
52 sc.save_annotated(
53     "render_two_fields_tf.png",
54     sigma_clip=6.0,
55     tf_rect=[0.88, 0.15, 0.03, 0.8],
56     render=False,
57 )
58
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/doc/source/cookbook/render_two_fields_tf.py b/doc/source/cookbook/render_two_fields_tf.py
--- a/doc/source/cookbook/render_two_fields_tf.py
+++ b/doc/source/cookbook/render_two_fields_tf.py
@@ -12,7 +12,6 @@
 # Add density
 
 field = "density"
-ds._get_field_info(field).take_log = True
 
 vol = create_volume_source(ds, field=field)
 vol.use_ghost_zones = True
@@ -27,7 +26,6 @@
 # Add temperature
 
 field = "temperature"
-ds._get_field_info(field).take_log = True
 
 vol2 = create_volume_source(ds, field=field)
 vol2.use_ghost_zones = True

{"golden_diff": "diff --git a/doc/source/cookbook/render_two_fields_tf.py b/doc/source/cookbook/render_two_fields_tf.py\n--- a/doc/source/cookbook/render_two_fields_tf.py\n+++ b/doc/source/cookbook/render_two_fields_tf.py\n@@ -12,7 +12,6 @@\n # Add density\n \n field = \"density\"\n-ds._get_field_info(field).take_log = True\n \n vol = create_volume_source(ds, field=field)\n vol.use_ghost_zones = True\n@@ -27,7 +26,6 @@\n # Add temperature\n \n field = \"temperature\"\n-ds._get_field_info(field).take_log = True\n \n vol2 = create_volume_source(ds, field=field)\n vol2.use_ghost_zones = True\n", "issue": "DOC: private methods used in cookbook recipe\n### Bug report\r\n\r\n**Bug summary**\r\n\r\nin #2567, `doc/source/cookbook/render_two_fields_tf.py` was added to the cookbook\r\nOn the two following lines, the private method `_get_field_info` is used\r\nhttps://github.com/yt-project/yt/blob/ef08989d8222e7172751d17009959102db05dd20/doc/source/cookbook/render_two_fields_tf.py#L15\r\nhttps://github.com/yt-project/yt/blob/ef08989d8222e7172751d17009959102db05dd20/doc/source/cookbook/render_two_fields_tf.py#L30\r\n\r\nThis should be refactored to avoid showing private elements\r\n@zingale, do you know how we could do this ?\n", "before_files": [{"content": "import numpy as np\n\nimport yt\nfrom yt.visualization.volume_rendering.api import Scene, create_volume_source\n\nds = yt.load(\"IsolatedGalaxy/galaxy0030/galaxy0030\")\n\n# create a scene and add volume sources to it\n\nsc = Scene()\n\n# Add density\n\nfield = \"density\"\nds._get_field_info(field).take_log = True\n\nvol = create_volume_source(ds, field=field)\nvol.use_ghost_zones = True\n\ntf = yt.ColorTransferFunction([-28, -25])\ntf.clear()\ntf.add_layers(4, 0.02, alpha=np.logspace(-3, -1, 4), colormap=\"winter\")\n\nvol.set_transfer_function(tf)\nsc.add_source(vol)\n\n# Add temperature\n\nfield = \"temperature\"\nds._get_field_info(field).take_log = True\n\nvol2 = create_volume_source(ds, field=field)\nvol2.use_ghost_zones = True\n\ntf = yt.ColorTransferFunction([4.5, 7.5])\ntf.clear()\ntf.add_layers(4, 0.02, alpha=np.logspace(-0.2, 0, 4), colormap=\"autumn\")\n\nvol2.set_transfer_function(tf)\nsc.add_source(vol2)\n\n# setup the camera\n\ncam = sc.add_camera(ds, lens_type=\"perspective\")\ncam.resolution = (1600, 900)\ncam.zoom(20.0)\n\n# Render the image.\n\nsc.render()\n\nsc.save_annotated(\n    \"render_two_fields_tf.png\",\n    sigma_clip=6.0,\n    tf_rect=[0.88, 0.15, 0.03, 0.8],\n    render=False,\n)\n", "path": "doc/source/cookbook/render_two_fields_tf.py"}], "after_files": [{"content": "import numpy as np\n\nimport yt\nfrom yt.visualization.volume_rendering.api import Scene, create_volume_source\n\nds = yt.load(\"IsolatedGalaxy/galaxy0030/galaxy0030\")\n\n# create a scene and add volume sources to it\n\nsc = Scene()\n\n# Add density\n\nfield = \"density\"\n\nvol = create_volume_source(ds, field=field)\nvol.use_ghost_zones = True\n\ntf = yt.ColorTransferFunction([-28, -25])\ntf.clear()\ntf.add_layers(4, 0.02, alpha=np.logspace(-3, -1, 4), colormap=\"winter\")\n\nvol.set_transfer_function(tf)\nsc.add_source(vol)\n\n# Add temperature\n\nfield = \"temperature\"\n\nvol2 = create_volume_source(ds, field=field)\nvol2.use_ghost_zones = True\n\ntf = yt.ColorTransferFunction([4.5, 7.5])\ntf.clear()\ntf.add_layers(4, 0.02, alpha=np.logspace(-0.2, 0, 4), colormap=\"autumn\")\n\nvol2.set_transfer_function(tf)\nsc.add_source(vol2)\n\n# setup the camera\n\ncam = sc.add_camera(ds, lens_type=\"perspective\")\ncam.resolution = (1600, 900)\ncam.zoom(20.0)\n\n# Render the image.\n\nsc.render()\n\nsc.save_annotated(\n    \"render_two_fields_tf.png\",\n    sigma_clip=6.0,\n    tf_rect=[0.88, 0.15, 0.03, 0.8],\n    render=False,\n)\n", "path": "doc/source/cookbook/render_two_fields_tf.py"}]}