prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Improve toil cluster utils CLI
  Instead of requiring the -p flag make it default to 'aws'. It would also be great to make the cluster name optional -- if the user only has 1 cluster running it should use that by default, else raise an error asking for an explicit argument
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `src/toil/utils/__init__.py`
  Content:
  ```
  1 from __future__ import absolute_import
  2 
  3 from toil import version
  4 import logging
  5 
  6 from toil.provisioners.aws import getCurrentAWSZone
  7 
  8 logger = logging.getLogger( __name__ )
  9 
  10 
  11 def addBasicProvisionerOptions(parser):
  12     parser.add_argument("--version", action='version', version=version)
  13     parser.add_argument('-p', "--provisioner", dest='provisioner', choices=['aws'], required=True,
  14                         help="The provisioner for cluster auto-scaling. Only aws is currently "
  15                              "supported")
  16     currentZone = getCurrentAWSZone()
  17     zoneString = currentZone if currentZone else 'No zone could be determined'
  18     parser.add_argument('-z', '--zone', dest='zone', required=False, default=currentZone,
  19                         help="The AWS availability zone of the master. This parameter can also be "
  20                              "set via the TOIL_AWS_ZONE environment variable, or by the ec2_region_name "
  21                              "parameter in your .boto file, or derived from the instance metadata if "
  22                              "using this utility on an existing EC2 instance. "
  23                              "Currently: %s" % zoneString)
  24     parser.add_argument("clusterName", help="The name that the cluster will be identifiable by. "
  25                                             "Must be lowercase and may not contain the '_' "
  26                                             "character.")
  27     return parser
  28
  ```
  --- 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/src/toil/utils/__init__.py b/src/toil/utils/__init__.py
  --- a/src/toil/utils/__init__.py
  +++ b/src/toil/utils/__init__.py
  @@ -5,12 +5,12 @@
   
   from toil.provisioners.aws import getCurrentAWSZone
   
  -logger = logging.getLogger( __name__ )
  +logger = logging.getLogger(__name__)
   
   
   def addBasicProvisionerOptions(parser):
       parser.add_argument("--version", action='version', version=version)
  -    parser.add_argument('-p', "--provisioner", dest='provisioner', choices=['aws'], required=True,
  +    parser.add_argument('-p', "--provisioner", dest='provisioner', choices=['aws'], required=False, default="aws",
                           help="The provisioner for cluster auto-scaling. Only aws is currently "
                                "supported")
       currentZone = getCurrentAWSZone()
  
verification_info: {"golden_diff": "diff --git a/src/toil/utils/__init__.py b/src/toil/utils/__init__.py\n--- a/src/toil/utils/__init__.py\n+++ b/src/toil/utils/__init__.py\n@@ -5,12 +5,12 @@\n \n from toil.provisioners.aws import getCurrentAWSZone\n \n-logger = logging.getLogger( __name__ )\n+logger = logging.getLogger(__name__)\n \n \n def addBasicProvisionerOptions(parser):\n     parser.add_argument(\"--version\", action='version', version=version)\n-    parser.add_argument('-p', \"--provisioner\", dest='provisioner', choices=['aws'], required=True,\n+    parser.add_argument('-p', \"--provisioner\", dest='provisioner', choices=['aws'], required=False, default=\"aws\",\n                         help=\"The provisioner for cluster auto-scaling. Only aws is currently \"\n                              \"supported\")\n     currentZone = getCurrentAWSZone()\n", "issue": "Improve toil cluster utils CLI\nInstead of requiring the -p flag make it default to 'aws'. It would also be great to make the cluster name optional -- if the user only has 1 cluster running it should use that by default, else raise an error asking for an explicit argument\n", "before_files": [{"content": "from __future__ import absolute_import\n\nfrom toil import version\nimport logging\n\nfrom toil.provisioners.aws import getCurrentAWSZone\n\nlogger = logging.getLogger( __name__ )\n\n\ndef addBasicProvisionerOptions(parser):\n    parser.add_argument(\"--version\", action='version', version=version)\n    parser.add_argument('-p', \"--provisioner\", dest='provisioner', choices=['aws'], required=True,\n                        help=\"The provisioner for cluster auto-scaling. Only aws is currently \"\n                             \"supported\")\n    currentZone = getCurrentAWSZone()\n    zoneString = currentZone if currentZone else 'No zone could be determined'\n    parser.add_argument('-z', '--zone', dest='zone', required=False, default=currentZone,\n                        help=\"The AWS availability zone of the master. This parameter can also be \"\n                             \"set via the TOIL_AWS_ZONE environment variable, or by the ec2_region_name \"\n                             \"parameter in your .boto file, or derived from the instance metadata if \"\n                             \"using this utility on an existing EC2 instance. \"\n                             \"Currently: %s\" % zoneString)\n    parser.add_argument(\"clusterName\", help=\"The name that the cluster will be identifiable by. \"\n                                            \"Must be lowercase and may not contain the '_' \"\n                                            \"character.\")\n    return parser\n", "path": "src/toil/utils/__init__.py"}], "after_files": [{"content": "from __future__ import absolute_import\n\nfrom toil import version\nimport logging\n\nfrom toil.provisioners.aws import getCurrentAWSZone\n\nlogger = logging.getLogger(__name__)\n\n\ndef addBasicProvisionerOptions(parser):\n    parser.add_argument(\"--version\", action='version', version=version)\n    parser.add_argument('-p', \"--provisioner\", dest='provisioner', choices=['aws'], required=False, default=\"aws\",\n                        help=\"The provisioner for cluster auto-scaling. Only aws is currently \"\n                             \"supported\")\n    currentZone = getCurrentAWSZone()\n    zoneString = currentZone if currentZone else 'No zone could be determined'\n    parser.add_argument('-z', '--zone', dest='zone', required=False, default=currentZone,\n                        help=\"The AWS availability zone of the master. This parameter can also be \"\n                             \"set via the TOIL_AWS_ZONE environment variable, or by the ec2_region_name \"\n                             \"parameter in your .boto file, or derived from the instance metadata if \"\n                             \"using this utility on an existing EC2 instance. \"\n                             \"Currently: %s\" % zoneString)\n    parser.add_argument(\"clusterName\", help=\"The name that the cluster will be identifiable by. \"\n                                            \"Must be lowercase and may not contain the '_' \"\n                                            \"character.\")\n    return parser\n", "path": "src/toil/utils/__init__.py"}]}