'Load :class:`JobInstrumenter` objects from specified configuration file.'

def __init__(self, conf_file=None, **kwargs):

    self.plugin_classes = self.__plugins_dict()
    self.default_job_instrumenter = JobInstrumenter.from_file(self.plugin_classes, conf_file, **kwargs)
    self.job_instrumenters = collections.defaultdict((lambda : self.default_job_instrumenter))
