beginning[e_tot] = 1e9   ! Just to keep parser happy. Does not do anything.
parameter[lattice_type] = linear_lattice
cavity2: lcavity, tracking_method = runge_kutta, mat6_calc_method = tracking,  
field_calc = grid, rf_frequency = 1.3e9,
field = { 
 mode = {
 m = 0,
grid = call::cavity2_grid.bmad }}
CALL, FILE = cavity2_wall.bmad

layout: line = (cavity2)
use, layout