'Get standard_stats: only for displayed processes.
Stats grabbed inside this method:
* nice and memory_info'

def __get_standard_stats(self, proc, procstat):

    procstat['standard_stats'] = True
    try:
        procstat.update(proc.as_dict(attrs=['nice', 'memory_info']))
    except psutil.NoSuchProcess:
        pass
    return procstat
