code: public EClass getIfcExtendedMaterialProperties() {
  		if (ifcExtendedMaterialPropertiesEClass == null) {
  			ifcExtendedMaterialPropertiesEClass = (EClass) EPackage.Registry.INSTANCE
  					.getEPackage(Ifc2x3tc1Package.eNS_URI).getEClassifiers().get(213);
  		}
  		return ifcExtendedMaterialPropertiesEClass;
  	}
docs: <!-- begin-user-doc -->
  <!-- end-user-doc -->
  @generated