async getProperties(modelID, id, indirect, recursive) {
            if (modelID == null || id == null)
                return null;
            const props = await this.loader.ifcManager.getItemProperties(modelID, id, recursive);
            if (indirect) {
                props.psets = await this.loader.ifcManager.getPropertySets(modelID, id, recursive);
                props.mats = await this.loader.ifcManager.getMaterialsProperties(modelID, id, recursive);
                props.type = await this.loader.ifcManager.getTypeProperties(modelID, id, recursive);
            }
            return props;
        }
Gets the properties of the specified item.
@modelID ID of the IFC model.
@id Express ID of the item.
@indirect If true, also returns psets, qsets and type properties.
@recursive If true, this gets the native properties of the referenced elements recursively.