docs: 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]