def multiply(traj):
z = traj.x * traj.y<EOL>traj.f_add_result('<STR_LIT:z>', z, comment='<STR_LIT>')<EOL>
Example of a sophisticated simulation that involves multiplying two values.

    :param traj:

        Trajectory containing
        the parameters in a particular combination,
        it also serves as a container for results.