nodes: 0, module; 1, function_definition; 2, function_name:_sort_io_counters; 3, parameters; 4, block; 5, identifier:process; 6, default_parameter; 7, default_parameter; 8, expression_statement; 9, return_statement; 10, identifier:sortedby; 11, string; 12, identifier:sortedby_secondary; 13, string; 14, comment:"""Specific case for io_counters
      Sum of io_r + io_w"""; 15, binary_operator:process[sortedby][0] - process[sortedby][2] + process[sortedby][1] - process[sortedby][3]; 16, string_content:io_counters; 17, string_content:memory_percent; 18, binary_operator:process[sortedby][0] - process[sortedby][2] + process[sortedby][1]; 19, subscript; 20, binary_operator:process[sortedby][0] - process[sortedby][2]; 21, subscript; 22, subscript; 23, integer:3; 24, subscript; 25, subscript; 26, subscript; 27, integer:1; 28, identifier:process; 29, identifier:sortedby; 30, subscript; 31, integer:0; 32, subscript; 33, integer:2; 34, identifier:process; 35, identifier:sortedby; 36, identifier:process; 37, identifier:sortedby; 38, identifier:process; 39, identifier:sortedby
code: 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]