First express ID after the last entity emitted.
Statistics for diagnostics / preview UI.
IfcRelAssignsToProduct edges (task outputs), one per output product.
IfcRelAssignsToControl edges whose RelatingControl is a calendar.
Counted separately from assignsToControl (schedule -> tasks) so a
caller can tell the two relationship kinds apart in a preview.
IfcRecurrencePattern entities emitted (one per IfcWorkTime that carried a pattern).
IfcTimePeriod entities emitted from those patterns' TimePeriods lists.
IfcWorkCalendar entities emitted.
IfcWorkTime entities emitted across every calendar's working + exception lists.
STEP entity lines (each terminated with
;).