code: def gw_run(self):
          
  
          if self.folder != os.getcwd():
              init_folder = os.getcwd()
              os.chdir(self.folder)
  
          with zopen(self.log_file, 'w') as fout:
              subprocess.call(["mpirun", "-n", str(self.mpi_procs), "fiesta",
                               str(self.grid[0]), str(self.grid[1]),
                               str(self.grid[2])], stdout=fout)
  
          if self.folder != os.getcwd():
              os.chdir(init_folder)
docs: Performs FIESTA (gw) run