How to use the ipython.logger.warning function in ipython

""" Launch scattered jobs: one job = one pbs script. """
    from copy import deepcopy
    import os
    import re
    import subprocess
    from os.path import exists, basename
    from os import remove
    import pylada
    from .. import get_shell
    from ...misc import local_path, testValidProgram
    from ... import pbs_string, default_pbs, qsub_exe, default_comm
    from . import get_walltime, get_mppalloc, get_queues, scattered_script
    from .. import logger

    if not hasattr(pylada, 'ipython_qstat'):
        logger.warning("Missing ipython_qstat function: cannot check for jobs already in queue")
        qstat = lambda x: []
    else:
        qstat = lambda x: self.qstat(x)

    logger.info("launch/scattered: event: %s" % event)
    shell = get_shell(self)

    pbsargs = deepcopy(dict(default_comm))
    pbsargs.update(default_pbs)
    pbsargs['ppn'] = event.ppn

    mppalloc = get_mppalloc(shell, event)
    if mppalloc is None:
        return

    # Set pbsargs['walltime'] to a string like '03:59:59'