def METHOD_NAME(state, derivs):
    nodes.numGhostNodes = 0
    nodes.neighbor().updateNodes()
    for bc in bcs:
        bc.setGhostNodes(nodes)
        bc.finalizeGhostBoundary()
        nodes.neighbor().updateNodes()
    for f in [nodes.mass(), nodes.massDensity()]:
        for bc in bcs:
            bc.applyGhostBoundary(f)
    hg.applyGhostBoundaries(state, derivs)
    return