We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Make NumPy the default frontend
Since we promised earlier:

```
  /home/jenkins/workspace/kymatio_dev/kymatio/frontend/entry.py:20: DeprecationWarning: Torch frontend is currently the default, but NumPy will become the default in the next version.
    warnings.warn("Torch frontend is currently the default, but NumPy will become the default in the next"
```

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `kymatio/frontend/entry.py`
Content:
```
1 import logging
2 import warnings
3 import importlib
4 
5 
6 class ScatteringEntry(object):
7     def __init__(self, *args, **kwargs):
8         self.name = kwargs['name']
9         self.class_name = kwargs['class_name']
10         kwargs.pop('name')
11         kwargs.pop('class_name')
12 
13         frontend_suffixes = {'torch' : 'Torch',
14                              'numpy' : 'NumPy',
15                              'tensorflow' : 'TensorFlow',
16                              'keras': 'Keras',
17                              'sklearn': 'Transformer'}
18 
19         if 'frontend' not in kwargs:
20             warnings.warn("Torch frontend is currently the default, but NumPy will become the default in the next"
21                           " version.", DeprecationWarning)
22             frontend = 'torch'
23         else:
24             frontend = kwargs['frontend'].lower()
25             kwargs.pop('frontend')
26 
27         frontends = list(frontend_suffixes.keys())
28 
29         if frontend not in frontends:
30             raise RuntimeError('The frontend \'%s\" is not valid. Must be '
31                                'one of \'%s\', or \'%s\'.' %
32                                (frontend, '\', \''.join(frontends[:-1]),
33                                 frontends[-1]))
34 
35         try:
36             module = importlib.import_module('kymatio.' + self.class_name + '.frontend.' + frontend + '_frontend')
37 
38             # Create frontend-specific class name by inserting frontend name
39             # after `Scattering`.
40             frontend = frontend_suffixes[frontend]
41 
42             class_name = self.__class__.__name__
43 
44             base_name = class_name[:-len('Entry*D')]
45             dim_suffix = class_name[-len('*D'):]
46 
47             class_name = base_name + frontend + dim_suffix
48 
49             self.__class__ = getattr(module, class_name)
50             self.__init__(*args, **kwargs)
51         except Exception as e:
52             raise e from RuntimeError('\nThe frontend \'' + frontend + '\' could not be correctly imported.')
53 
54         logging.info('The ' + self.name + ' frontend ' + frontend + ' was imported.')
55 
56 
57 __all__ = ['ScatteringEntry']
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/kymatio/frontend/entry.py b/kymatio/frontend/entry.py
--- a/kymatio/frontend/entry.py
+++ b/kymatio/frontend/entry.py
@@ -17,9 +17,7 @@
                              'sklearn': 'Transformer'}
 
         if 'frontend' not in kwargs:
-            warnings.warn("Torch frontend is currently the default, but NumPy will become the default in the next"
-                          " version.", DeprecationWarning)
-            frontend = 'torch'
+            frontend = 'numpy'
         else:
             frontend = kwargs['frontend'].lower()
             kwargs.pop('frontend')

{"golden_diff": "diff --git a/kymatio/frontend/entry.py b/kymatio/frontend/entry.py\n--- a/kymatio/frontend/entry.py\n+++ b/kymatio/frontend/entry.py\n@@ -17,9 +17,7 @@\n                              'sklearn': 'Transformer'}\n \n         if 'frontend' not in kwargs:\n-            warnings.warn(\"Torch frontend is currently the default, but NumPy will become the default in the next\"\n-                          \" version.\", DeprecationWarning)\n-            frontend = 'torch'\n+            frontend = 'numpy'\n         else:\n             frontend = kwargs['frontend'].lower()\n             kwargs.pop('frontend')\n", "issue": "Make NumPy the default frontend\nSince we promised earlier:\r\n\r\n```\r\n  /home/jenkins/workspace/kymatio_dev/kymatio/frontend/entry.py:20: DeprecationWarning: Torch frontend is currently the default, but NumPy will become the default in the next version.\r\n    warnings.warn(\"Torch frontend is currently the default, but NumPy will become the default in the next\"\r\n```\n", "before_files": [{"content": "import logging\nimport warnings\nimport importlib\n\n\nclass ScatteringEntry(object):\n    def __init__(self, *args, **kwargs):\n        self.name = kwargs['name']\n        self.class_name = kwargs['class_name']\n        kwargs.pop('name')\n        kwargs.pop('class_name')\n\n        frontend_suffixes = {'torch' : 'Torch',\n                             'numpy' : 'NumPy',\n                             'tensorflow' : 'TensorFlow',\n                             'keras': 'Keras',\n                             'sklearn': 'Transformer'}\n\n        if 'frontend' not in kwargs:\n            warnings.warn(\"Torch frontend is currently the default, but NumPy will become the default in the next\"\n                          \" version.\", DeprecationWarning)\n            frontend = 'torch'\n        else:\n            frontend = kwargs['frontend'].lower()\n            kwargs.pop('frontend')\n\n        frontends = list(frontend_suffixes.keys())\n\n        if frontend not in frontends:\n            raise RuntimeError('The frontend \\'%s\\\" is not valid. Must be '\n                               'one of \\'%s\\', or \\'%s\\'.' %\n                               (frontend, '\\', \\''.join(frontends[:-1]),\n                                frontends[-1]))\n\n        try:\n            module = importlib.import_module('kymatio.' + self.class_name + '.frontend.' + frontend + '_frontend')\n\n            # Create frontend-specific class name by inserting frontend name\n            # after `Scattering`.\n            frontend = frontend_suffixes[frontend]\n\n            class_name = self.__class__.__name__\n\n            base_name = class_name[:-len('Entry*D')]\n            dim_suffix = class_name[-len('*D'):]\n\n            class_name = base_name + frontend + dim_suffix\n\n            self.__class__ = getattr(module, class_name)\n            self.__init__(*args, **kwargs)\n        except Exception as e:\n            raise e from RuntimeError('\\nThe frontend \\'' + frontend + '\\' could not be correctly imported.')\n\n        logging.info('The ' + self.name + ' frontend ' + frontend + ' was imported.')\n\n\n__all__ = ['ScatteringEntry']\n", "path": "kymatio/frontend/entry.py"}], "after_files": [{"content": "import logging\nimport warnings\nimport importlib\n\n\nclass ScatteringEntry(object):\n    def __init__(self, *args, **kwargs):\n        self.name = kwargs['name']\n        self.class_name = kwargs['class_name']\n        kwargs.pop('name')\n        kwargs.pop('class_name')\n\n        frontend_suffixes = {'torch' : 'Torch',\n                             'numpy' : 'NumPy',\n                             'tensorflow' : 'TensorFlow',\n                             'keras': 'Keras',\n                             'sklearn': 'Transformer'}\n\n        if 'frontend' not in kwargs:\n            frontend = 'numpy'\n        else:\n            frontend = kwargs['frontend'].lower()\n            kwargs.pop('frontend')\n\n        frontends = list(frontend_suffixes.keys())\n\n        if frontend not in frontends:\n            raise RuntimeError('The frontend \\'%s\\\" is not valid. Must be '\n                               'one of \\'%s\\', or \\'%s\\'.' %\n                               (frontend, '\\', \\''.join(frontends[:-1]),\n                                frontends[-1]))\n\n        try:\n            module = importlib.import_module('kymatio.' + self.class_name + '.frontend.' + frontend + '_frontend')\n\n            # Create frontend-specific class name by inserting frontend name\n            # after `Scattering`.\n            frontend = frontend_suffixes[frontend]\n\n            class_name = self.__class__.__name__\n\n            base_name = class_name[:-len('Entry*D')]\n            dim_suffix = class_name[-len('*D'):]\n\n            class_name = base_name + frontend + dim_suffix\n\n            self.__class__ = getattr(module, class_name)\n            self.__init__(*args, **kwargs)\n        except Exception as e:\n            raise e from RuntimeError('\\nThe frontend \\'' + frontend + '\\' could not be correctly imported.')\n\n        logging.info('The ' + self.name + ' frontend ' + frontend + ' was imported.')\n\n\n__all__ = ['ScatteringEntry']\n", "path": "kymatio/frontend/entry.py"}]}