prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Remove version model
  **Describe the bug**
  The version model is not used currently and should be removed
  
  https://github.com/fossasia/open-event-server/blob/development/app/models/version.py
  
  
  **Additional context**
  @iamareebjamal Taking 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: `app/models/version.py`
  Content:
  ```
  1 from sqlalchemy.orm import backref
  2 
  3 from app.models import db
  4 
  5 
  6 class Version(db.Model):
  7     """Version model class"""
  8     __tablename__ = 'versions'
  9     id = db.Column(db.Integer, primary_key=True)
  10     event_id = db.Column(db.Integer, db.ForeignKey('events.id', ondelete='CASCADE'))
  11     events = db.relationship("Event", backref=backref('version', uselist=False))
  12 
  13     event_ver = db.Column(db.Integer, nullable=False, default=0)
  14     sessions_ver = db.Column(db.Integer, nullable=False, default=0)
  15     speakers_ver = db.Column(db.Integer, nullable=False, default=0)
  16     tracks_ver = db.Column(db.Integer, nullable=False, default=0)
  17     sponsors_ver = db.Column(db.Integer, nullable=False, default=0)
  18     microlocations_ver = db.Column(db.Integer, nullable=False, default=0)
  19 
  20     def __init__(self,
  21                  event_id=None,
  22                  event_ver=None,
  23                  sessions_ver=None,
  24                  speakers_ver=None,
  25                  tracks_ver=None,
  26                  sponsors_ver=None,
  27                  microlocations_ver=None):
  28         self.event_id = event_id
  29         self.event_ver = event_ver
  30         self.sessions_ver = sessions_ver
  31         self.speakers_ver = speakers_ver
  32         self.tracks_ver = tracks_ver
  33         self.sponsors_ver = sponsors_ver
  34         self.microlocations_ver = microlocations_ver
  35 
  36     def __repr__(self):
  37         return '<Version %r>' % self.id
  38 
  39     def __str__(self):
  40         return self.__repr__()
  41 
  42     @property
  43     def serialize(self):
  44         """Return object data in easily serializable format"""
  45         return {
  46             'version': [
  47                 {'id': self.id,
  48                  'event_id': self.event_id,
  49                  'event_ver': self.event_ver,
  50                  'sessions_ver': self.sessions_ver,
  51                  'speakers_ver': self.speakers_ver,
  52                  'tracks_ver': self.tracks_ver,
  53                  'sponsors_ver': self.sponsors_ver,
  54                  'microlocations_ver': self.microlocations_ver}
  55             ]
  56         }
  57
  ```
  --- 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/app/models/version.py b/app/models/version.py
  deleted file mode 100644
  --- a/app/models/version.py
  +++ /dev/null
  @@ -1,56 +0,0 @@
  -from sqlalchemy.orm import backref
  -
  -from app.models import db
  -
  -
  -class Version(db.Model):
  -    """Version model class"""
  -    __tablename__ = 'versions'
  -    id = db.Column(db.Integer, primary_key=True)
  -    event_id = db.Column(db.Integer, db.ForeignKey('events.id', ondelete='CASCADE'))
  -    events = db.relationship("Event", backref=backref('version', uselist=False))
  -
  -    event_ver = db.Column(db.Integer, nullable=False, default=0)
  -    sessions_ver = db.Column(db.Integer, nullable=False, default=0)
  -    speakers_ver = db.Column(db.Integer, nullable=False, default=0)
  -    tracks_ver = db.Column(db.Integer, nullable=False, default=0)
  -    sponsors_ver = db.Column(db.Integer, nullable=False, default=0)
  -    microlocations_ver = db.Column(db.Integer, nullable=False, default=0)
  -
  -    def __init__(self,
  -                 event_id=None,
  -                 event_ver=None,
  -                 sessions_ver=None,
  -                 speakers_ver=None,
  -                 tracks_ver=None,
  -                 sponsors_ver=None,
  -                 microlocations_ver=None):
  -        self.event_id = event_id
  -        self.event_ver = event_ver
  -        self.sessions_ver = sessions_ver
  -        self.speakers_ver = speakers_ver
  -        self.tracks_ver = tracks_ver
  -        self.sponsors_ver = sponsors_ver
  -        self.microlocations_ver = microlocations_ver
  -
  -    def __repr__(self):
  -        return '<Version %r>' % self.id
  -
  -    def __str__(self):
  -        return self.__repr__()
  -
  -    @property
  -    def serialize(self):
  -        """Return object data in easily serializable format"""
  -        return {
  -            'version': [
  -                {'id': self.id,
  -                 'event_id': self.event_id,
  -                 'event_ver': self.event_ver,
  -                 'sessions_ver': self.sessions_ver,
  -                 'speakers_ver': self.speakers_ver,
  -                 'tracks_ver': self.tracks_ver,
  -                 'sponsors_ver': self.sponsors_ver,
  -                 'microlocations_ver': self.microlocations_ver}
  -            ]
  -        }
  
verification_info: {"golden_diff": "diff --git a/app/models/version.py b/app/models/version.py\ndeleted file mode 100644\n--- a/app/models/version.py\n+++ /dev/null\n@@ -1,56 +0,0 @@\n-from sqlalchemy.orm import backref\n-\n-from app.models import db\n-\n-\n-class Version(db.Model):\n-    \"\"\"Version model class\"\"\"\n-    __tablename__ = 'versions'\n-    id = db.Column(db.Integer, primary_key=True)\n-    event_id = db.Column(db.Integer, db.ForeignKey('events.id', ondelete='CASCADE'))\n-    events = db.relationship(\"Event\", backref=backref('version', uselist=False))\n-\n-    event_ver = db.Column(db.Integer, nullable=False, default=0)\n-    sessions_ver = db.Column(db.Integer, nullable=False, default=0)\n-    speakers_ver = db.Column(db.Integer, nullable=False, default=0)\n-    tracks_ver = db.Column(db.Integer, nullable=False, default=0)\n-    sponsors_ver = db.Column(db.Integer, nullable=False, default=0)\n-    microlocations_ver = db.Column(db.Integer, nullable=False, default=0)\n-\n-    def __init__(self,\n-                 event_id=None,\n-                 event_ver=None,\n-                 sessions_ver=None,\n-                 speakers_ver=None,\n-                 tracks_ver=None,\n-                 sponsors_ver=None,\n-                 microlocations_ver=None):\n-        self.event_id = event_id\n-        self.event_ver = event_ver\n-        self.sessions_ver = sessions_ver\n-        self.speakers_ver = speakers_ver\n-        self.tracks_ver = tracks_ver\n-        self.sponsors_ver = sponsors_ver\n-        self.microlocations_ver = microlocations_ver\n-\n-    def __repr__(self):\n-        return '<Version %r>' % self.id\n-\n-    def __str__(self):\n-        return self.__repr__()\n-\n-    @property\n-    def serialize(self):\n-        \"\"\"Return object data in easily serializable format\"\"\"\n-        return {\n-            'version': [\n-                {'id': self.id,\n-                 'event_id': self.event_id,\n-                 'event_ver': self.event_ver,\n-                 'sessions_ver': self.sessions_ver,\n-                 'speakers_ver': self.speakers_ver,\n-                 'tracks_ver': self.tracks_ver,\n-                 'sponsors_ver': self.sponsors_ver,\n-                 'microlocations_ver': self.microlocations_ver}\n-            ]\n-        }\n", "issue": "Remove version model\n**Describe the bug**\r\nThe version model is not used currently and should be removed\r\n\r\nhttps://github.com/fossasia/open-event-server/blob/development/app/models/version.py\r\n\r\n\r\n**Additional context**\r\n@iamareebjamal Taking this\r\n\n", "before_files": [{"content": "from sqlalchemy.orm import backref\n\nfrom app.models import db\n\n\nclass Version(db.Model):\n    \"\"\"Version model class\"\"\"\n    __tablename__ = 'versions'\n    id = db.Column(db.Integer, primary_key=True)\n    event_id = db.Column(db.Integer, db.ForeignKey('events.id', ondelete='CASCADE'))\n    events = db.relationship(\"Event\", backref=backref('version', uselist=False))\n\n    event_ver = db.Column(db.Integer, nullable=False, default=0)\n    sessions_ver = db.Column(db.Integer, nullable=False, default=0)\n    speakers_ver = db.Column(db.Integer, nullable=False, default=0)\n    tracks_ver = db.Column(db.Integer, nullable=False, default=0)\n    sponsors_ver = db.Column(db.Integer, nullable=False, default=0)\n    microlocations_ver = db.Column(db.Integer, nullable=False, default=0)\n\n    def __init__(self,\n                 event_id=None,\n                 event_ver=None,\n                 sessions_ver=None,\n                 speakers_ver=None,\n                 tracks_ver=None,\n                 sponsors_ver=None,\n                 microlocations_ver=None):\n        self.event_id = event_id\n        self.event_ver = event_ver\n        self.sessions_ver = sessions_ver\n        self.speakers_ver = speakers_ver\n        self.tracks_ver = tracks_ver\n        self.sponsors_ver = sponsors_ver\n        self.microlocations_ver = microlocations_ver\n\n    def __repr__(self):\n        return '<Version %r>' % self.id\n\n    def __str__(self):\n        return self.__repr__()\n\n    @property\n    def serialize(self):\n        \"\"\"Return object data in easily serializable format\"\"\"\n        return {\n            'version': [\n                {'id': self.id,\n                 'event_id': self.event_id,\n                 'event_ver': self.event_ver,\n                 'sessions_ver': self.sessions_ver,\n                 'speakers_ver': self.speakers_ver,\n                 'tracks_ver': self.tracks_ver,\n                 'sponsors_ver': self.sponsors_ver,\n                 'microlocations_ver': self.microlocations_ver}\n            ]\n        }\n", "path": "app/models/version.py"}], "after_files": [{"content": null, "path": "app/models/version.py"}]}