Function classification_schema 

pub fn classification_schema(
    model: &Model,
) -> ClassificationResult<SchemaVersion>

The IFC release model’s classification records are read against.

IFC2X3 binds the IFC2X3 table. Any other single declaration, and a header with none, binds IFC4 (IFC4X3 is not yet read against its own table). A consumer binds its vocabulary with this answer instead of re-parsing the header.

Errors

ClassificationError::MultipleSchemas when the header declares several schemas including IFC2X3, so no single release can be bound.