How to use the cloudaux.aws.sts.sts_conn function in cloudaux

@sts_conn('iam', service_type='client')
@rate_limited()
def get_managed_policy_document(policy_arn, policy_metadata=None, client=None, **kwargs):
    """Retrieve the currently active (i.e. 'default') policy version document for a policy.

    :param policy_arn:
    :param policy_metadata: This is a previously fetch managed policy response from boto/cloudaux.
                            This is used to prevent unnecessary API calls to get the initial policy default version id.
    :param client:
    :param kwargs:
    :return:
    """
    if not policy_metadata:
        policy_metadata = client.get_policy(PolicyArn=policy_arn)

    policy_document = client.get_policy_version(PolicyArn=policy_arn,
                                                VersionId=policy_metadata['Policy']['DefaultVersionId'])

@sts_conn('sqs')
@rate_limited()
def set_queue_attributes(client=None, **kwargs):
    return client.set_queue_attributes(**kwargs)

@sts_conn('sns')
@rate_limited()
def delete_topic(client=None, **kwargs):
    return client.delete_topic(**kwargs)

@sts_conn('ec2')
@rate_limited()
def create_group(group, account_number=None, region=None, assume_role=None, client=None):
    if group.vpc_id:
        group_id = client.create_security_group(
                GroupName=group.name,
                Description=group.description,
                VpcId=group.vpc_id
        )['GroupId']
    else:
        group_id = client.create_security_group(
                GroupName=group.name,
                Description=group.description
        )['GroupId']

    return group_id

@sts_conn('sns')
@paginated('Endpoints', request_pagination_marker="NextToken", response_pagination_marker="NextToken")
@rate_limited()
def list_endpoints_by_platform_application(client=None, **kwargs):
    return client.list_endpoints_by_platform_application(**kwargs)

@sts_conn('sqs')
@rate_limited()
def send_message_batch(client=None, **kwargs):
    return client.send_message_batch(**kwargs)

@sts_conn('sqs')
@rate_limited()
def get_queue_url(client=None, **kwargs):
    return client.get_queue_url(**kwargs)['QueueUrl']

@sts_conn('ec2')
@rate_limited()
def authorize_rule(rule, group, account_number=None, region=None, assume_role=None, client=None):
    if rule.direction == 'egress':
        # response = client.authorize_security_group_egress()
        raise CloudAuxException("Modifying egress rules is not yet supported.")
    else:
        if rule.cidr:
            client.authorize_security_group_ingress(
                    GroupId=group.aws_group_id,
                    IpProtocol=rule.protocol,
                    FromPort=rule.from_port,
                    ToPort=rule.to_port,
                    CidrIp=rule.cidr
            )
        else:
            client.authorize_security_group_ingress(

@sts_conn('ec2')
@rate_limited()
def describe_vpn_connections(**kwargs):
    return kwargs.pop('client').describe_vpn_connections(**kwargs).get("VpnConnections", [])

@sts_conn('s3')
@rate_limited()
def list_buckets(client=None, **kwargs):
    return client.list_buckets()