We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
[BUG] `Cannot find serializable class` raised when calling set_label
When calling DataFrame.columns=xxxx in distributed environment, a KeyError is raised with message `Cannot find serializable class for type_id 1517314310`.

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `mars/dataframe/indexing/__init__.py`
Content:
```
1 # Copyright 1999-2020 Alibaba Group Holding Ltd.
2 #
3 # Licensed under the Apache License, Version 2.0 (the "License");
4 # you may not use this file except in compliance with the License.
5 # You may obtain a copy of the License at
6 #
7 #      http://www.apache.org/licenses/LICENSE-2.0
8 #
9 # Unless required by applicable law or agreed to in writing, software
10 # distributed under the License is distributed on an "AS IS" BASIS,
11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 # See the License for the specific language governing permissions and
13 # limitations under the License.
14 
15 
16 def _install():
17     from pandas.util import cache_readonly
18     from ..operands import DATAFRAME_TYPE, SERIES_TYPE, INDEX_TYPE
19     from .at import at
20     from .getitem import dataframe_getitem, series_getitem
21     from .iat import iat
22     from .iloc import iloc, head, tail
23     from .insert import df_insert
24     from .loc import loc
25     from .rename import df_rename, series_rename, index_rename
26     from .reset_index import df_reset_index, series_reset_index
27     from .set_index import set_index
28     from .setitem import dataframe_setitem
29     from .reindex import reindex
30     from .where import mask, where
31 
32     for cls in DATAFRAME_TYPE + SERIES_TYPE:
33         setattr(cls, 'iloc', cache_readonly(iloc))
34         setattr(cls, 'loc', cache_readonly(loc))
35         setattr(cls, 'iat', cache_readonly(iat))
36         setattr(cls, 'at', cache_readonly(at))
37         setattr(cls, 'reindex', reindex)
38         setattr(cls, 'head', head)
39         setattr(cls, 'tail', tail)
40         setattr(cls, 'mask', mask)
41         setattr(cls, 'where', where)
42 
43     for cls in DATAFRAME_TYPE:
44         setattr(cls, 'set_index', set_index)
45         setattr(cls, '__getitem__', dataframe_getitem)
46         setattr(cls, '__setitem__', dataframe_setitem)
47         setattr(cls, 'insert', df_insert)
48         setattr(cls, 'reset_index', df_reset_index)
49         setattr(cls, 'rename', df_rename)
50 
51     for cls in SERIES_TYPE:
52         setattr(cls, '__getitem__', series_getitem)
53         setattr(cls, 'reset_index', series_reset_index)
54         setattr(cls, 'rename', series_rename)
55 
56     for cls in INDEX_TYPE:
57         setattr(cls, 'rename', index_rename)
58 
59 
60 _install()
61 del _install
62
```
--- 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/mars/dataframe/indexing/__init__.py b/mars/dataframe/indexing/__init__.py
--- a/mars/dataframe/indexing/__init__.py
+++ b/mars/dataframe/indexing/__init__.py
@@ -56,6 +56,10 @@
     for cls in INDEX_TYPE:
         setattr(cls, 'rename', index_rename)
 
+    # make sure operand is registered
+    from .set_label import DataFrameSetLabel
+    del DataFrameSetLabel
+
 
 _install()
 del _install

{"golden_diff": "diff --git a/mars/dataframe/indexing/__init__.py b/mars/dataframe/indexing/__init__.py\n--- a/mars/dataframe/indexing/__init__.py\n+++ b/mars/dataframe/indexing/__init__.py\n@@ -56,6 +56,10 @@\n     for cls in INDEX_TYPE:\n         setattr(cls, 'rename', index_rename)\n \n+    # make sure operand is registered\n+    from .set_label import DataFrameSetLabel\n+    del DataFrameSetLabel\n+\n \n _install()\n del _install\n", "issue": "[BUG] `Cannot find serializable class` raised when calling set_label\nWhen calling DataFrame.columns=xxxx in distributed environment, a KeyError is raised with message `Cannot find serializable class for type_id 1517314310`.\n", "before_files": [{"content": "# Copyright 1999-2020 Alibaba Group Holding Ltd.\n#\n# Licensed under the Apache License, Version 2.0 (the \"License\");\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n#\n#      http://www.apache.org/licenses/LICENSE-2.0\n#\n# Unless required by applicable law or agreed to in writing, software\n# distributed under the License is distributed on an \"AS IS\" BASIS,\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n# limitations under the License.\n\n\ndef _install():\n    from pandas.util import cache_readonly\n    from ..operands import DATAFRAME_TYPE, SERIES_TYPE, INDEX_TYPE\n    from .at import at\n    from .getitem import dataframe_getitem, series_getitem\n    from .iat import iat\n    from .iloc import iloc, head, tail\n    from .insert import df_insert\n    from .loc import loc\n    from .rename import df_rename, series_rename, index_rename\n    from .reset_index import df_reset_index, series_reset_index\n    from .set_index import set_index\n    from .setitem import dataframe_setitem\n    from .reindex import reindex\n    from .where import mask, where\n\n    for cls in DATAFRAME_TYPE + SERIES_TYPE:\n        setattr(cls, 'iloc', cache_readonly(iloc))\n        setattr(cls, 'loc', cache_readonly(loc))\n        setattr(cls, 'iat', cache_readonly(iat))\n        setattr(cls, 'at', cache_readonly(at))\n        setattr(cls, 'reindex', reindex)\n        setattr(cls, 'head', head)\n        setattr(cls, 'tail', tail)\n        setattr(cls, 'mask', mask)\n        setattr(cls, 'where', where)\n\n    for cls in DATAFRAME_TYPE:\n        setattr(cls, 'set_index', set_index)\n        setattr(cls, '__getitem__', dataframe_getitem)\n        setattr(cls, '__setitem__', dataframe_setitem)\n        setattr(cls, 'insert', df_insert)\n        setattr(cls, 'reset_index', df_reset_index)\n        setattr(cls, 'rename', df_rename)\n\n    for cls in SERIES_TYPE:\n        setattr(cls, '__getitem__', series_getitem)\n        setattr(cls, 'reset_index', series_reset_index)\n        setattr(cls, 'rename', series_rename)\n\n    for cls in INDEX_TYPE:\n        setattr(cls, 'rename', index_rename)\n\n\n_install()\ndel _install\n", "path": "mars/dataframe/indexing/__init__.py"}], "after_files": [{"content": "# Copyright 1999-2020 Alibaba Group Holding Ltd.\n#\n# Licensed under the Apache License, Version 2.0 (the \"License\");\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n#\n#      http://www.apache.org/licenses/LICENSE-2.0\n#\n# Unless required by applicable law or agreed to in writing, software\n# distributed under the License is distributed on an \"AS IS\" BASIS,\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n# limitations under the License.\n\n\ndef _install():\n    from pandas.util import cache_readonly\n    from ..operands import DATAFRAME_TYPE, SERIES_TYPE, INDEX_TYPE\n    from .at import at\n    from .getitem import dataframe_getitem, series_getitem\n    from .iat import iat\n    from .iloc import iloc, head, tail\n    from .insert import df_insert\n    from .loc import loc\n    from .rename import df_rename, series_rename, index_rename\n    from .reset_index import df_reset_index, series_reset_index\n    from .set_index import set_index\n    from .setitem import dataframe_setitem\n    from .reindex import reindex\n    from .where import mask, where\n\n    for cls in DATAFRAME_TYPE + SERIES_TYPE:\n        setattr(cls, 'iloc', cache_readonly(iloc))\n        setattr(cls, 'loc', cache_readonly(loc))\n        setattr(cls, 'iat', cache_readonly(iat))\n        setattr(cls, 'at', cache_readonly(at))\n        setattr(cls, 'reindex', reindex)\n        setattr(cls, 'head', head)\n        setattr(cls, 'tail', tail)\n        setattr(cls, 'mask', mask)\n        setattr(cls, 'where', where)\n\n    for cls in DATAFRAME_TYPE:\n        setattr(cls, 'set_index', set_index)\n        setattr(cls, '__getitem__', dataframe_getitem)\n        setattr(cls, '__setitem__', dataframe_setitem)\n        setattr(cls, 'insert', df_insert)\n        setattr(cls, 'reset_index', df_reset_index)\n        setattr(cls, 'rename', df_rename)\n\n    for cls in SERIES_TYPE:\n        setattr(cls, '__getitem__', series_getitem)\n        setattr(cls, 'reset_index', series_reset_index)\n        setattr(cls, 'rename', series_rename)\n\n    for cls in INDEX_TYPE:\n        setattr(cls, 'rename', index_rename)\n\n    # make sure operand is registered\n    from .set_label import DataFrameSetLabel\n    del DataFrameSetLabel\n\n\n_install()\ndel _install\n", "path": "mars/dataframe/indexing/__init__.py"}]}