bool AddInternalPayload ( const [FSdfPath](API\Plugins\UnrealUSDWrapper\UsdWrappers\FSdfPath) & PrimPath, const [FSdfLayerOffset](API\Plugins\UnrealUSDWrapper\UsdWrappers\FSdfLayerOffset) & LayerOffset, [EUsdListPosition](API\Plugins\UnrealUSDWrapper\EUsdListPosition) Position )