Sets the Interim status (step_status) of a system activity to completed (step_status = 99). For more details, see the TechDoc.
Please note: When using the functions setTableValue, setSubtableValue and setSystemActivityVar the data is not written to the database until the function markActivityAsCompleted is called.
Example:
if( $this->isCompleted() === false ){
$this->markActivityAsCompleted();
}