How to use the taskcluster.Scheduler function in taskcluster

""" It schedules a TaskCluster graph and returns its id.

    :param task_graph: It is a TaskCluster graph as defined in here:
        http://docs.taskcluster.net/scheduler/api-docs/#createTaskGraph
    :type task_graph: json
    :param task_graph_id: TC graph id to which this task belongs to
    :type task_graph_id: str
    :param dry_run: It does not schedule the graph
    :type dry_run: bool
    :returns: task graph id.
    :rtype: int

    """
    if not task_graph_id:
        task_graph_id = taskcluster_client.slugId()
    scheduler = taskcluster_client.Scheduler()

    LOG.info("Outputting the graph (graph id: %s):" % task_graph_id)
    # We print to stdout instead of using the standard logging with dates and info levels
    # XXX: Use a different formatter for other tools to work better with this code
    print(json.dumps(task_graph, indent=4))
    if dry_run:
        LOG.info("DRY-RUN: We have not scheduled the graph.")
    else:
        if not credentials_available():
            return None

        try:
            # https://github.com/taskcluster/taskcluster-client.py#create-new-task-graph
            result = scheduler.createTaskGraph(task_graph_id, task_graph)
            LOG.info("See the graph in %s%s" % (TC_TASK_GRAPH_INSPECTOR, task_graph_id))
            return result

def get_task_graph_status(task_graph_id):
    """ Returns state of a Task-Graph Status Response
    """
    scheduler = taskcluster_client.Scheduler()
    response = scheduler.status(task_graph_id)
    return response['status']['state']

def get_task_graph_status(task_graph_id):
    """ Returns state of a Task-Graph Status Response
    """
    scheduler = taskcluster_client.Scheduler()
    response = scheduler.status(task_graph_id)
    return response['status']['state']

def extend_task_graph(task_graph_id, task_graph, dry_run=False):
    """

    From: http://docs.taskcluster.net/scheduler/api-docs/#extendTaskGraph

    Safety, it is only safe to call this API end-point while the task-graph
    being modified is still running. If the task-graph is finished or blocked,
    this method will leave the task-graph in this state. Hence, it is only
    truly safe to call this API end-point from within a task in the task-graph
    being modified.

    returns Task-Graph Status Response
    """
    # XXX: handle the case when the task-graph is not running
    scheduler = taskcluster_client.Scheduler()
    if dry_run:
        LOG.info("DRY-RUN: We have not extended the graph.")
    else:
        LOG.debug("When extending a graph we don't need metadata and scopes.")
        del task_graph['metadata']
        del task_graph['scopes']
        print(json.dumps(task_graph, indent=4))
        return scheduler.extendTaskGraph(task_graph_id, task_graph)

""" It schedules a TaskCluster graph and returns its id.

    :param task_graph: It is a TaskCluster graph as defined in here:
        http://docs.taskcluster.net/scheduler/api-docs/#createTaskGraph
    :type task_graph: json
    :param task_graph_id: TC graph id to which this task belongs to
    :type task_graph_id: str
    :param dry_run: It does not schedule the graph
    :type dry_run: bool
    :returns: task graph id.
    :rtype: int

    """
    if not task_graph_id:
        task_graph_id = taskcluster_client.slugId()
    scheduler = taskcluster_client.Scheduler()

    LOG.info("Outputting the graph (graph id: %s):" % task_graph_id)
    # We print to stdout instead of using the standard logging with dates and info levels
    # XXX: Use a different formatter for other tools to work better with this code
    print(json.dumps(task_graph, indent=4))
    if dry_run:
        LOG.info("DRY-RUN: We have not scheduled the graph.")
    else:
        if not credentials_available():
            return None

        try:
            # https://github.com/taskcluster/taskcluster-client.py#create-new-task-graph
            result = scheduler.createTaskGraph(task_graph_id, task_graph)
            LOG.info("See the graph in %s%s" % (TC_TASK_GRAPH_INSPECTOR, task_graph_id))
            return result

def extend_task_graph(task_graph_id, task_graph, dry_run=False):
    """

    From: http://docs.taskcluster.net/scheduler/api-docs/#extendTaskGraph

    Safety, it is only safe to call this API end-point while the task-graph
    being modified is still running. If the task-graph is finished or blocked,
    this method will leave the task-graph in this state. Hence, it is only
    truly safe to call this API end-point from within a task in the task-graph
    being modified.

    returns Task-Graph Status Response
    """
    # XXX: handle the case when the task-graph is not running
    scheduler = taskcluster_client.Scheduler()
    if dry_run:
        LOG.info("DRY-RUN: We have not extended the graph.")
    else:
        LOG.debug("When extending a graph we don't need metadata and scopes.")
        del task_graph['metadata']
        del task_graph['scopes']
        print(json.dumps(task_graph, indent=4))
        return scheduler.extendTaskGraph(task_graph_id, task_graph)