Add students or professors to an existing training.

Without options, the students are also added to every future attendance sheet, document and survey of the training.
"Future" covers every unlocked course of the training that has not ended yet, ongoing courses included.
Students already in the training are skipped and added to nothing.

The students' groups are not taken into account: each student is added to every course of the training, whatever its groups.
The effect grows with the size of the training: one student added to a training of 3,000 courses is put on 3,000 attendance sheets.

To only enrol the students in the training, send options with every flag set to false, as in the example below.
When options is sent, all six flags are required (a missing flag is rejected), and only the resources whose flag is true are updated.