null: disactivating a stream

The typical use of the null driver is to make (embedded) models silent by disabling their output, either from the host application embedding the model 'mod' (Mosel C libraries):

XPRMsetdefstream(mod, XPRM_F_WRITE, "null:");

Similarly with other library interfaces, such as with the Mosel Java library:

mod.setDefaultStream(XPRM.F_OUTPUT, "null:");

Or from within Mosel, such as in the master model that controls the execution of a submodel 'submod':

setdefstream(submod, F_OUTPUT, "null:")

Or even directly in the (sub)model itself:

fopen(F_OUTPUT, "null:")