prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Use the bug snapshot transform in the "uplift" model
  Depends on #5.
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `bugbug/models/uplift.py`
  Content:
  ```
  1 # -*- coding: utf-8 -*-
  2 # This Source Code Form is subject to the terms of the Mozilla Public
  3 # License, v. 2.0. If a copy of the MPL was not distributed with this file,
  4 # You can obtain one at http://mozilla.org/MPL/2.0/.
  5 
  6 import xgboost
  7 from imblearn.under_sampling import RandomUnderSampler
  8 from sklearn.compose import ColumnTransformer
  9 from sklearn.feature_extraction import DictVectorizer
  10 from sklearn.pipeline import Pipeline
  11 
  12 from bugbug import bug_features
  13 from bugbug import bugzilla
  14 from bugbug.model import Model
  15 
  16 
  17 class UpliftModel(Model):
  18     def __init__(self, lemmatization=False):
  19         Model.__init__(self, lemmatization)
  20 
  21         self.sampler = RandomUnderSampler(random_state=0)
  22 
  23         feature_extractors = [
  24             bug_features.has_str(),
  25             bug_features.has_regression_range(),
  26             bug_features.severity(),
  27             bug_features.keywords(),
  28             bug_features.is_coverity_issue(),
  29             bug_features.has_crash_signature(),
  30             bug_features.has_url(),
  31             bug_features.has_w3c_url(),
  32             bug_features.has_github_url(),
  33             bug_features.whiteboard(),
  34             bug_features.patches(),
  35             bug_features.landings(),
  36             bug_features.title(),
  37         ]
  38 
  39         cleanup_functions = [
  40             bug_features.cleanup_fileref,
  41             bug_features.cleanup_url,
  42             bug_features.cleanup_synonyms,
  43         ]
  44 
  45         self.extraction_pipeline = Pipeline([
  46             ('bug_extractor', bug_features.BugExtractor(feature_extractors, cleanup_functions)),
  47             ('union', ColumnTransformer([
  48                 ('data', DictVectorizer(), 'data'),
  49 
  50                 ('title', self.text_vectorizer(), 'title'),
  51 
  52                 ('comments', self.text_vectorizer(), 'comments'),
  53             ])),
  54         ])
  55 
  56         self.clf = xgboost.XGBClassifier(n_jobs=16)
  57         self.clf.set_params(predictor='cpu_predictor')
  58 
  59     def get_labels(self):
  60         classes = {}
  61 
  62         for bug_data in bugzilla.get_bugs():
  63             bug_id = int(bug_data['id'])
  64 
  65             for attachment in bug_data['attachments']:
  66                 for flag in attachment['flags']:
  67                     if not flag['name'].startswith('approval-mozilla-') or flag['status'] not in ['+', '-']:
  68                         continue
  69 
  70                     if flag['status'] == '+':
  71                         classes[bug_id] = 1
  72                     elif flag['status'] == '-':
  73                         classes[bug_id] = 0
  74 
  75         return classes
  76 
  77     def get_feature_names(self):
  78         return self.extraction_pipeline.named_steps['union'].get_feature_names()
  79
  ```
  --- 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()
  
  ```
  
golden_diff: diff --git a/bugbug/models/uplift.py b/bugbug/models/uplift.py
  --- a/bugbug/models/uplift.py
  +++ b/bugbug/models/uplift.py
  @@ -43,7 +43,7 @@
           ]
   
           self.extraction_pipeline = Pipeline([
  -            ('bug_extractor', bug_features.BugExtractor(feature_extractors, cleanup_functions)),
  +            ('bug_extractor', bug_features.BugExtractor(feature_extractors, cleanup_functions, rollback=True, rollback_when=self.rollback)),
               ('union', ColumnTransformer([
                   ('data', DictVectorizer(), 'data'),
   
  @@ -56,6 +56,9 @@
           self.clf = xgboost.XGBClassifier(n_jobs=16)
           self.clf.set_params(predictor='cpu_predictor')
   
  +    def rollback(self, change):
  +        return (change['field_name'] == 'flagtypes.name' and change['added'].startswith('approval-mozilla-') and (change['added'].endswith('+') or change['added'].endswith('-')))
  +
       def get_labels(self):
           classes = {}
  
verification_info: {"golden_diff": "diff --git a/bugbug/models/uplift.py b/bugbug/models/uplift.py\n--- a/bugbug/models/uplift.py\n+++ b/bugbug/models/uplift.py\n@@ -43,7 +43,7 @@\n         ]\n \n         self.extraction_pipeline = Pipeline([\n-            ('bug_extractor', bug_features.BugExtractor(feature_extractors, cleanup_functions)),\n+            ('bug_extractor', bug_features.BugExtractor(feature_extractors, cleanup_functions, rollback=True, rollback_when=self.rollback)),\n             ('union', ColumnTransformer([\n                 ('data', DictVectorizer(), 'data'),\n \n@@ -56,6 +56,9 @@\n         self.clf = xgboost.XGBClassifier(n_jobs=16)\n         self.clf.set_params(predictor='cpu_predictor')\n \n+    def rollback(self, change):\n+        return (change['field_name'] == 'flagtypes.name' and change['added'].startswith('approval-mozilla-') and (change['added'].endswith('+') or change['added'].endswith('-')))\n+\n     def get_labels(self):\n         classes = {}\n", "issue": "Use the bug snapshot transform in the \"uplift\" model\nDepends on #5.\n", "before_files": [{"content": "# -*- coding: utf-8 -*-\n# This Source Code Form is subject to the terms of the Mozilla Public\n# License, v. 2.0. If a copy of the MPL was not distributed with this file,\n# You can obtain one at http://mozilla.org/MPL/2.0/.\n\nimport xgboost\nfrom imblearn.under_sampling import RandomUnderSampler\nfrom sklearn.compose import ColumnTransformer\nfrom sklearn.feature_extraction import DictVectorizer\nfrom sklearn.pipeline import Pipeline\n\nfrom bugbug import bug_features\nfrom bugbug import bugzilla\nfrom bugbug.model import Model\n\n\nclass UpliftModel(Model):\n    def __init__(self, lemmatization=False):\n        Model.__init__(self, lemmatization)\n\n        self.sampler = RandomUnderSampler(random_state=0)\n\n        feature_extractors = [\n            bug_features.has_str(),\n            bug_features.has_regression_range(),\n            bug_features.severity(),\n            bug_features.keywords(),\n            bug_features.is_coverity_issue(),\n            bug_features.has_crash_signature(),\n            bug_features.has_url(),\n            bug_features.has_w3c_url(),\n            bug_features.has_github_url(),\n            bug_features.whiteboard(),\n            bug_features.patches(),\n            bug_features.landings(),\n            bug_features.title(),\n        ]\n\n        cleanup_functions = [\n            bug_features.cleanup_fileref,\n            bug_features.cleanup_url,\n            bug_features.cleanup_synonyms,\n        ]\n\n        self.extraction_pipeline = Pipeline([\n            ('bug_extractor', bug_features.BugExtractor(feature_extractors, cleanup_functions)),\n            ('union', ColumnTransformer([\n                ('data', DictVectorizer(), 'data'),\n\n                ('title', self.text_vectorizer(), 'title'),\n\n                ('comments', self.text_vectorizer(), 'comments'),\n            ])),\n        ])\n\n        self.clf = xgboost.XGBClassifier(n_jobs=16)\n        self.clf.set_params(predictor='cpu_predictor')\n\n    def get_labels(self):\n        classes = {}\n\n        for bug_data in bugzilla.get_bugs():\n            bug_id = int(bug_data['id'])\n\n            for attachment in bug_data['attachments']:\n                for flag in attachment['flags']:\n                    if not flag['name'].startswith('approval-mozilla-') or flag['status'] not in ['+', '-']:\n                        continue\n\n                    if flag['status'] == '+':\n                        classes[bug_id] = 1\n                    elif flag['status'] == '-':\n                        classes[bug_id] = 0\n\n        return classes\n\n    def get_feature_names(self):\n        return self.extraction_pipeline.named_steps['union'].get_feature_names()\n", "path": "bugbug/models/uplift.py"}], "after_files": [{"content": "# -*- coding: utf-8 -*-\n# This Source Code Form is subject to the terms of the Mozilla Public\n# License, v. 2.0. If a copy of the MPL was not distributed with this file,\n# You can obtain one at http://mozilla.org/MPL/2.0/.\n\nimport xgboost\nfrom imblearn.under_sampling import RandomUnderSampler\nfrom sklearn.compose import ColumnTransformer\nfrom sklearn.feature_extraction import DictVectorizer\nfrom sklearn.pipeline import Pipeline\n\nfrom bugbug import bug_features\nfrom bugbug import bugzilla\nfrom bugbug.model import Model\n\n\nclass UpliftModel(Model):\n    def __init__(self, lemmatization=False):\n        Model.__init__(self, lemmatization)\n\n        self.sampler = RandomUnderSampler(random_state=0)\n\n        feature_extractors = [\n            bug_features.has_str(),\n            bug_features.has_regression_range(),\n            bug_features.severity(),\n            bug_features.keywords(),\n            bug_features.is_coverity_issue(),\n            bug_features.has_crash_signature(),\n            bug_features.has_url(),\n            bug_features.has_w3c_url(),\n            bug_features.has_github_url(),\n            bug_features.whiteboard(),\n            bug_features.patches(),\n            bug_features.landings(),\n            bug_features.title(),\n        ]\n\n        cleanup_functions = [\n            bug_features.cleanup_fileref,\n            bug_features.cleanup_url,\n            bug_features.cleanup_synonyms,\n        ]\n\n        self.extraction_pipeline = Pipeline([\n            ('bug_extractor', bug_features.BugExtractor(feature_extractors, cleanup_functions, rollback=True, rollback_when=self.rollback)),\n            ('union', ColumnTransformer([\n                ('data', DictVectorizer(), 'data'),\n\n                ('title', self.text_vectorizer(), 'title'),\n\n                ('comments', self.text_vectorizer(), 'comments'),\n            ])),\n        ])\n\n        self.clf = xgboost.XGBClassifier(n_jobs=16)\n        self.clf.set_params(predictor='cpu_predictor')\n\n    def rollback(self, change):\n        return (change['field_name'] == 'flagtypes.name' and change['added'].startswith('approval-mozilla-') and (change['added'].endswith('+') or change['added'].endswith('-')))\n\n    def get_labels(self):\n        classes = {}\n\n        for bug_data in bugzilla.get_bugs():\n            bug_id = int(bug_data['id'])\n\n            for attachment in bug_data['attachments']:\n                for flag in attachment['flags']:\n                    if not flag['name'].startswith('approval-mozilla-') or flag['status'] not in ['+', '-']:\n                        continue\n\n                    if flag['status'] == '+':\n                        classes[bug_id] = 1\n                    elif flag['status'] == '-':\n                        classes[bug_id] = 0\n\n        return classes\n\n    def get_feature_names(self):\n        return self.extraction_pipeline.named_steps['union'].get_feature_names()\n", "path": "bugbug/models/uplift.py"}]}