text: /*
   * Copyright (c) Facebook, Inc. and its affiliates.
   *
   * This source code is licensed under the MIT license found in the
   * LICENSE file in the root directory of this source tree.
   */
  
  #pragma once
  
  #include <filesystem>
  #include <istream>
  #include <ostream>
  #include <string>
  #include <unordered_map>
  #include <vector>
  
  namespace pid::combiner {
  /*
  This file implements the sortIds that is used to sort data files based on id
  in order to return a sorted file
  
  For example, if for  index 'id', specified columns are val1 and val 2
  and this input file content:
  id        val1       val2        val3
  2           z         [c]         v3
  3           q         [l]         v4
  1           x       [a,b,c]       v1
  
  
  The output would be a sorted list based on the id key:
  id        val1       val2        val3
  1           x       [a,b,c]       v1
  2           z         [c]         v3
  3           q         [l]         v4
  */
  void sortIds(std::istream& inFilePath, std::ostream& outFilePath);
  } // namespace pid::combiner
  