OptionalownerExpress ID of an existing IfcOwnerHistory to reference, if the host
file has one. When omitted, every emitted entity uses $ for ownership.
OptionalresolveLook up an existing express ID for a product GlobalId (for binding
IfcRelAssignsToProcess.RelatedObjects and
IfcRelAssignsToProduct.RelatingProduct). When omitted, or when it
returns undefined, the product's own positive expressId is used; a
product with neither is skipped — the schedule is still valid IFC, just
without that product link.
First free express ID for the synthesized entities.