[igraph] Error in i.parse.plot.params(graph, list(...)) : Unknown plot parameters: label.color, label.dist

[Kun Deng]

The following snippet in the igraph tutorial won't run: 
> g <- barabasi.game(100, directed=FALSE)
> d <- get.diameter(g)
> E(g)$color <- "SkyBlue2"
> E(g)$width <- 1
> E(g, path=d)$color <- "red"
> E(g, path=d)$width <- 2
> V(g)$labelcolor <- V(g)$color  <- "blue"
> V(g)[ d ]$labelcolor <- V(g)[ d ]$color <- "red"
> plot(g, layout=layout.kamada.kawai, 
     edge.color=E(g)$color,edge.width=E(g)$width,
     vertex.color=V(g)$color, label.color=V(g)$labelcolor,
     label.dist=0.4, vertex.size=3)

The error is :
Error in i.parse.plot.params(graph, list(...)) :    Unknown plot parameters: label.color, label.dist
Can someone please help?