anchor.diff:  
     T = PTread_d(config, 'T', loc=params_group)
     do_hydro = PTread_l(config, 'do_hydro', loc=params_group)
  +  do_thermostat = PTread_l(config, 'do_thermostat', loc=params_group)
     
     tau = PTread_d(config, 'tau', loc=params_group)
     mpcd_alpha = PTread_d(config,'alpha', loc=params_group)
  
positive.code: 
       call wall_mpcd_step(solvent, solvent_cells, state, &
            wall_temperature=[T, T], wall_v=wall_v, wall_n=[rho, rho], &
            alpha=mpcd_alpha, keep_cell_v=do_hydro, thermostat=.not.do_hydro, &
            bulk_temperature=T)
       call compute_cell_wise_max_v
  
  
negative.code: 
    logical :: do_rattle, do_read_links, do_lennard_jones, do_elastic, do_quaternion, do_solvent_io
    logical :: do_hydro
    logical :: do_thermostat
    logical :: do_ywall
    integer, allocatable :: links(:,:)
    double precision, allocatable :: links_d(:)
  