code: @SuppressWarnings("unchecked")
  	@Override
  	public EList<IfcRelAssignsToGroup> getIsGroupedBy() {
  		return (EList<IfcRelAssignsToGroup>) eGet(Ifc4Package.Literals.IFC_GROUP__IS_GROUPED_BY, true);
  	}
docs: <!-- begin-user-doc -->
  <!-- end-user-doc -->
  @generated