def _sort_io_counters(process,
                      sortedby='io_counters',
                      sortedby_secondary='memory_percent'):
    """Specific case for io_counters
    Sum of io_r + io_w"""
    return process[sortedby][0] - process[sortedby][2] + process[sortedby][1] - process[sortedby][3]
Specific case for io_counters
    Sum of io_r + io_w