IOdictionary propsDict(IOobject("particleTrackProperties", runTime.constant(), mesh, IOobject::MUST_READ_IF_MODIFIED))
List< word > userFields(propsDict.lookup("fields"))
const word dictName("particleTrackDict")
IOobject dictIO(dictName, runTime.constant(), mesh, IOobject::MUST_READ_IF_MODIFIED, IOobject::NO_WRITE)
const word cloudName(propsDict.lookup("cloudName"))