How to use the click.group function in click

@click.group('aiida-quantumespresso', context_settings={'help_option_names': ['-h', '--help']})
@options.PROFILE(type=types.ProfileParamType(load_profile=True))
def root(profile):  # pylint: disable=unused-argument
    """CLI for the `aiida-quantumespresso` plugin."""

@click.group(name='server')
def cli_server():
    """Subcommand `vserver-server`."""
    pass

@click.group()
def cli():
    pass

@click.group()
@click.pass_context
def cli(ctx):
    pass

@click.group()
def communities():
    """communities management commands."""

@click.group()
@click.option("--debug/--no-debug", help='set debug flag')
def cli(debug):
    'An example click script to test click-web'
    global DEBUG
    DEBUG = debug

@click.group()
def extensioncli(**kwargs):
    pass

@click.group()
def ocli():
    pass

@click.group(context_settings=CLICK_CONTEXT_SETTINGS)
def main():
    """Ghost generates a secret-store in which you can
    keep your secrets encrypted. Ghost isn't real. It's just in your head.

@click.group()
def cli():
    pass