Function declare 

pub fn declare(
    tx: &mut Transaction,
    global_id: &str,
    context: EntityId,
    definitions: &[EntityId],
) -> SpatialAuthoringResult<EntityId>

Stage an IfcRelDeclares: definitions declared in a context.

The context is an IfcProject or IfcProjectLibrary. This is how type objects and property set templates enter a file without being attached to any occurrence.

Errors

Refuses a malformed GlobalId, an empty definition set, and the context listed among its own declarations.