prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Fix intent default value to all examples, migration intent required
  
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `bothub/common/migrations/0021_auto_20180921_1259.py`
  Content:
  ```
  1 # Generated by Django 2.0.6 on 2018-09-21 12:59
  2 
  3 import django.core.validators
  4 from django.db import migrations, models
  5 import re
  6 
  7 
  8 class Migration(migrations.Migration):
  9 
  10     dependencies = [
  11         ('common', '0020_auto_20180813_1320'),
  12     ]
  13 
  14     operations = [
  15         migrations.AlterField(
  16             model_name='repositoryexample',
  17             name='intent',
  18             field=models.CharField(default='no_intent', help_text='Example intent reference', max_length=64, validators=[django.core.validators.RegexValidator(re.compile('^[-a-z0-9_]+\\Z'), 'Enter a valid value consisting of lowercase letters, numbers, underscores or hyphens.', 'invalid')], verbose_name='intent'),
  19         ),
  20     ]
  21
  ```
  --- 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/bothub/common/migrations/0021_auto_20180921_1259.py b/bothub/common/migrations/0021_auto_20180921_1259.py
  --- a/bothub/common/migrations/0021_auto_20180921_1259.py
  +++ b/bothub/common/migrations/0021_auto_20180921_1259.py
  @@ -5,6 +5,11 @@
   import re
   
   
  +def populate_empty_intent(apps, *args):
  +    RepositoryExample = apps.get_model('common', 'RepositoryExample')
  +    RepositoryExample.objects.filter(intent='').update(intent='no_intent')
  +
  +
   class Migration(migrations.Migration):
   
       dependencies = [
  @@ -17,4 +22,5 @@
               name='intent',
               field=models.CharField(default='no_intent', help_text='Example intent reference', max_length=64, validators=[django.core.validators.RegexValidator(re.compile('^[-a-z0-9_]+\\Z'), 'Enter a valid value consisting of lowercase letters, numbers, underscores or hyphens.', 'invalid')], verbose_name='intent'),
           ),
  +        migrations.RunPython(populate_empty_intent),
       ]
  
verification_info: {"golden_diff": "diff --git a/bothub/common/migrations/0021_auto_20180921_1259.py b/bothub/common/migrations/0021_auto_20180921_1259.py\n--- a/bothub/common/migrations/0021_auto_20180921_1259.py\n+++ b/bothub/common/migrations/0021_auto_20180921_1259.py\n@@ -5,6 +5,11 @@\n import re\n \n \n+def populate_empty_intent(apps, *args):\n+    RepositoryExample = apps.get_model('common', 'RepositoryExample')\n+    RepositoryExample.objects.filter(intent='').update(intent='no_intent')\n+\n+\n class Migration(migrations.Migration):\n \n     dependencies = [\n@@ -17,4 +22,5 @@\n             name='intent',\n             field=models.CharField(default='no_intent', help_text='Example intent reference', max_length=64, validators=[django.core.validators.RegexValidator(re.compile('^[-a-z0-9_]+\\\\Z'), 'Enter a valid value consisting of lowercase letters, numbers, underscores or hyphens.', 'invalid')], verbose_name='intent'),\n         ),\n+        migrations.RunPython(populate_empty_intent),\n     ]\n", "issue": "Fix intent default value to all examples, migration intent required\n\n", "before_files": [{"content": "# Generated by Django 2.0.6 on 2018-09-21 12:59\n\nimport django.core.validators\nfrom django.db import migrations, models\nimport re\n\n\nclass Migration(migrations.Migration):\n\n    dependencies = [\n        ('common', '0020_auto_20180813_1320'),\n    ]\n\n    operations = [\n        migrations.AlterField(\n            model_name='repositoryexample',\n            name='intent',\n            field=models.CharField(default='no_intent', help_text='Example intent reference', max_length=64, validators=[django.core.validators.RegexValidator(re.compile('^[-a-z0-9_]+\\\\Z'), 'Enter a valid value consisting of lowercase letters, numbers, underscores or hyphens.', 'invalid')], verbose_name='intent'),\n        ),\n    ]\n", "path": "bothub/common/migrations/0021_auto_20180921_1259.py"}], "after_files": [{"content": "# Generated by Django 2.0.6 on 2018-09-21 12:59\n\nimport django.core.validators\nfrom django.db import migrations, models\nimport re\n\n\ndef populate_empty_intent(apps, *args):\n    RepositoryExample = apps.get_model('common', 'RepositoryExample')\n    RepositoryExample.objects.filter(intent='').update(intent='no_intent')\n\n\nclass Migration(migrations.Migration):\n\n    dependencies = [\n        ('common', '0020_auto_20180813_1320'),\n    ]\n\n    operations = [\n        migrations.AlterField(\n            model_name='repositoryexample',\n            name='intent',\n            field=models.CharField(default='no_intent', help_text='Example intent reference', max_length=64, validators=[django.core.validators.RegexValidator(re.compile('^[-a-z0-9_]+\\\\Z'), 'Enter a valid value consisting of lowercase letters, numbers, underscores or hyphens.', 'invalid')], verbose_name='intent'),\n        ),\n        migrations.RunPython(populate_empty_intent),\n    ]\n", "path": "bothub/common/migrations/0021_auto_20180921_1259.py"}]}