text: #ifndef SYSTEM_H
  #define SYSTEM_H
  
  #include <string>
  #include <vector>
  
  #include "process.h"
  #include "processor.h"
  
  class System {
   public:
    Processor Cpu();                   // TODO: See src/system.cpp
    std::vector<Process>& Processes();  // TODO: See src/system.cpp
    float MemoryUtilization();          // TODO: See src/system.cpp
    long UpTime();                      // TODO: See src/system.cpp
    int TotalProcesses();               // TODO: See src/system.cpp
    int RunningProcesses();             // TODO: See src/system.cpp
    std::string Kernel();               // TODO: See src/system.cpp
    std::string OperatingSystem();      // TODO: See src/system.cpp
  
    // TODO: Define any necessary private members
   private:
    Processor cpu_ = {};
    std::vector<Process> processes_ = {};
  };
  
  #define whitespaces " \t\n\r\f\v"
  
  std::string open_text_file(std::string filename);
  std::string grep(std::string string0, std::string pattern);
  std::string isolate_string(std::string line, std::string left_pattern, std::string right_pattern);
  std::string substring(std::string s, std::size_t index0, std::size_t index1);
  long pick_long(std::string s, std::size_t index0, std::size_t index1);
  
  #endif
  