def freeze(h, output_yaml, resolve, groups):
    """Output installed packages."""
    if not groups:
        groups = filter(lambda group: not group.lower().startswith("bower"),
                        h.requirements.keys())
    else:
        groups = [text_type.strip(group) for group in groups.split(",")]

    if output_yaml:
        for requirements in h.requirements.values():
            for requirement in requirements:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
        click.echo(h.requirements.yaml)
    else:
        for group in groups:
            if not h.requirements[group]:
                continue
            click.echo("# {}".format(group))
            for requirement in h.requirements[group]:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
                click.echo(str(requirement))
def Exists(self):
    """Returns True if the log group exists."""
    describe_cmd = util.AWS_PREFIX + [
        '--region', self.region,
        'logs', 'describe-log-groups',
        '--log-group-name-prefix', self.name,
        '--no-paginate'
    ]
    stdout, _, _ = vm_util.IssueCommand(describe_cmd)
    log_groups = json.loads(stdout)['logGroups']
    group = next((group for group in log_groups
                  if group['logGroupName'] == self.name), None)
    return bool(group)