How to use the ipython.launch.get_walltime function in ipython

import subprocess
    from copy import deepcopy
    from os.path import dirname, join, basename, exists
    from IPython import get_ipython
    from ...misc import local_path
    from ... import pbs_string, default_pbs, qsub_exe, default_comm,       \
        interactive
    from . import get_walltime, get_queues, get_mppalloc
    from . import array_script

    shell = get_ipython()

    pbsargs = deepcopy(dict(default_comm))
    pbsargs.update(default_pbs)
    pbsargs['ppn'] = event.ppn
    if not get_walltime(shell, event, pbsargs):
        return
    if not get_queues(shell, event, pbsargs):
        return

    # gets python script to launch in pbs.
    pyscript = array_script.__file__
    if pyscript[-1] == 'c':
        pyscript = pyscript[:-1]

    # creates file names.
    hasprefix = getattr(event, "prefix", None)

    def pbspaths(directory, jobname, suffix):
        """ creates filename paths. """
        return join(join(directory, jobname),
                    '{0}-pbs{1}'.format(event.prefix, suffix) if hasprefix

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'
    if not get_walltime(shell, event, pbsargs):
        return

    # Set pbsargs['queue'], pbsargs['account']
    if not get_queues(shell, event, pbsargs):
        return
    logger.info("launch/scattered: pbsargs: %s" % pbsargs)

    # gets python script to launch in pbs.
    pyscript = scattered_script.__file__
    logger.info("launch/scattered: pyscript: %s" % pyscript)
    if pyscript[-1] == 'c':
        pyscript = pyscript[:-1]   # change .pyc to .py

    # creates file names.
    hasprefix = getattr(event, "prefix", None)