Open a terminal and navigate to the build directory. Launch the following command which will open the graphical interface of Vitis HLS and configure the project based on the settings included in the hls_opt.tcl Tcl file:
user@server:~$ cd ./build
user@server:~$ vitis_hls -p hls_opt.tcl &
Once the tool comes up, on the left-hand side, locate the Explorer pane, expand proj->Source and double-click on tsp_opt.cpp to inspect the source code.
The testbench is found below in proj->TestBench in the file is tsp_TB.cpp.