Function execute_cics 

pub fn execute_cics<'w>(
    compiled: &Compiled,
    code: &Code,
    library: Library,
    dds: Dds,
    task: Task,
    clock: Clock,
    database: Option<&'w mut (dyn Database + '_)>,
    out: &'w mut dyn Write,
    err: &'w mut dyn Write,
    observer: Option<Observer<'w>>,
    kept: &mut Option<Remains>,
) -> (Result<Ending, Halt>, Task)

Runs compiled, lowered as code, on the VM as the first program of a CICS task, as Execute::execute_cics_observed runs it on the interpreter; kept takes what the run left in its run unit, and the task comes back however the run ended.