Helper struct to choose the correct index for phases and components. This is need if the porous-medium-flow model features more fluid phases than the free-flow model. More...
| stokesIdx | The domain index of the free-flow model. | 
| darcyIdx | The domain index of the porous-medium-flow model. | 
| FFFS | The free-flow fluidsystem. | 
| hasAdapter | Specifies whether an adapter class for the fluidsystem is used. |