prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  AttributeError: url on Storage Exception when key not found
  When attempting to get a key that does not exist the exception for the `NotFoundError` is trying to reference `request.url` which does not exist.
  
  ``` py
  Traceback (most recent call last):
    [...]
      file_key = self.bucket.get_key(path)
    File "gcloud/storage/bucket.py", line 83, in get_key
      response = self.connection.api_request(method='GET', path=key.path)
    File "gcloud/storage/connection.py", line 212, in api_request
      raise exceptions.NotFoundError(response, content)
    File "gcloud/storage/exceptions.py", line 17, in __init__
      self.message = 'GET %s returned a 404.' % (response.url)
    File "httplib2/__init__.py", line 1680, in __getattr__
      raise AttributeError, name
  AttributeError: url
  ```
  
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `gcloud/storage/exceptions.py`
  Content:
  ```
  1 # TODO: Make these super useful.
  2 
  3 class StorageError(Exception):
  4   pass
  5 
  6 
  7 class ConnectionError(StorageError):
  8 
  9   def __init__(self, response, content):
  10     message = str(response) + content
  11     super(ConnectionError, self).__init__(message)
  12 
  13 
  14 class NotFoundError(ConnectionError):
  15 
  16   def __init__(self, response, content):
  17     self.message = 'GET %s returned a 404.' % (response.url)
  18 
  19 
  20 class StorageDataError(StorageError):
  21   pass
  22
  ```
  --- 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/gcloud/storage/exceptions.py b/gcloud/storage/exceptions.py
  --- a/gcloud/storage/exceptions.py
  +++ b/gcloud/storage/exceptions.py
  @@ -14,7 +14,7 @@
   class NotFoundError(ConnectionError):
   
     def __init__(self, response, content):
  -    self.message = 'GET %s returned a 404.' % (response.url)
  +    self.message = 'Request returned a 404. Headers: %s' % (response)
   
   
   class StorageDataError(StorageError):
  
verification_info: {"golden_diff": "diff --git a/gcloud/storage/exceptions.py b/gcloud/storage/exceptions.py\n--- a/gcloud/storage/exceptions.py\n+++ b/gcloud/storage/exceptions.py\n@@ -14,7 +14,7 @@\n class NotFoundError(ConnectionError):\n \n   def __init__(self, response, content):\n-    self.message = 'GET %s returned a 404.' % (response.url)\n+    self.message = 'Request returned a 404. Headers: %s' % (response)\n \n \n class StorageDataError(StorageError):\n", "issue": "AttributeError: url on Storage Exception when key not found\nWhen attempting to get a key that does not exist the exception for the `NotFoundError` is trying to reference `request.url` which does not exist.\n\n``` py\nTraceback (most recent call last):\n  [...]\n    file_key = self.bucket.get_key(path)\n  File \"gcloud/storage/bucket.py\", line 83, in get_key\n    response = self.connection.api_request(method='GET', path=key.path)\n  File \"gcloud/storage/connection.py\", line 212, in api_request\n    raise exceptions.NotFoundError(response, content)\n  File \"gcloud/storage/exceptions.py\", line 17, in __init__\n    self.message = 'GET %s returned a 404.' % (response.url)\n  File \"httplib2/__init__.py\", line 1680, in __getattr__\n    raise AttributeError, name\nAttributeError: url\n```\n\n", "before_files": [{"content": "# TODO: Make these super useful.\n\nclass StorageError(Exception):\n  pass\n\n\nclass ConnectionError(StorageError):\n\n  def __init__(self, response, content):\n    message = str(response) + content\n    super(ConnectionError, self).__init__(message)\n\n\nclass NotFoundError(ConnectionError):\n\n  def __init__(self, response, content):\n    self.message = 'GET %s returned a 404.' % (response.url)\n\n\nclass StorageDataError(StorageError):\n  pass\n", "path": "gcloud/storage/exceptions.py"}], "after_files": [{"content": "# TODO: Make these super useful.\n\nclass StorageError(Exception):\n  pass\n\n\nclass ConnectionError(StorageError):\n\n  def __init__(self, response, content):\n    message = str(response) + content\n    super(ConnectionError, self).__init__(message)\n\n\nclass NotFoundError(ConnectionError):\n\n  def __init__(self, response, content):\n    self.message = 'Request returned a 404. Headers: %s' % (response)\n\n\nclass StorageDataError(StorageError):\n  pass\n", "path": "gcloud/storage/exceptions.py"}]}