stm<std::string , int >  mach;try{// add two status node p_s1 as start , and p_s2 as end;stm<std::string,  int >::stStatus * p_s1 = mach.add( "ready" ); // specify the start node which id is 0mach.startStatus();stm<std::string , int > :: stStatus *p_s2 = mach.add("end" );// specify the end node with node pointer.mach.endStatus( p_s2 );// add convert arc , which trigged by a interger number of 1mach.addArc( p_s1 , p_s2 , 1 );// 从这里开始int data;while( true ){  // 通过键盘输入状态转换命令std::cout << "Input command: ";std::cin >> data;stm<std::string , int >::stStatus * f = nullptr, * e = nullptr;bool isOK = false;  // 触发状态转换mach.trigger( data , [&isOK ,  &f , &e ]( bool isTransOk , stm<std::string , int >::stStatus * from , stm<std::string, int >::stStatus * end ){   // do something before convert;   isOK = isTransOk;   f = from;   e = end;                           });// do something after convert;std::cerr << "CURRENT STATUS: " << mach.getCurrent() << std::endl;if( mach.isEnd( e ) == true ){std::cerr << "the machine is finished" << std::endl;break;}  }}catch( std::bad_alloc& e ){std::cerr << "Allocate memory fail" << std::endl;ret = -1;}return ret;