PottsMeshGenerator(unsigned numNodesAcross, unsigned numElementsAcross, unsigned elementWidth, unsigned numNodesUp=1u, unsigned numElementsUp=1u, unsigned elementHeight=1u, unsigned numNodesDeep=1u, unsigned numElementsDeep=1u, unsigned elementDepth=1u, bool startAtBottomLeft=false, bool isPeriodicInX=false, bool isPeriodicInY=false, bool isPeriodicInZ=false)