docstr: Setup: manage.py output set-from-file [options]
  
  Args:
      outputs (list): List of available output services
docstr_tok: ["Setup",":","manage.py","output","set-from-file","[","options","]","Args",":","outputs","(","list",")",":","List","of","available","output","services"]
code: def setup_subparser(cls, subparser):
      """Setup: manage.py output set-from-file [options]
  
      Args:
          outputs (list): List of available output services
      """
      set_from_file_parser = generate_subparser(
          subparser,
          "set-from-file",
          description=cls.description,
          help=cls.description,
          subcommand=True,
      )
  
      # Add the optional file flag
      set_from_file_parser.add_argument(
          "--file",
          "-f",
          default=OUTPUTS_FILE,
          help="Path to the json file, relative to the current working directory",
      )
  
      # Add the optional update flag, which allows existing outputs to be updated
      set_from_file_parser.add_argument(
          "--update",
          "-u",
          action="store_true",
          default=False,
          help="Allow existing outputs to be overwritten",
      )
  
imports: import json
  from streamalert.shared.logger import get_logger
  from streamalert.alert_processor.outputs.output_base import StreamAlertOutput, OutputCredentialsProvider
  from streamalert_cli.helpers import user_input, response_is_valid
  from streamalert_cli.outputs.helpers import output_exists
  from streamalert_cli.utils import CLICommand, generate_subparser
label_desc: Use image node_id 1 for calling the OutputSetFromFileSubCommand obj's underlying member method code with example usage: obj.setup_subparser(cls, subparser) without return types