Robust/Cluster in Tobit appear not to work

[Christopher Gandrud]

library(Zelig)
data(tobin)

# Create "clustering" variable
tobin$cl <- sample(x = 1:4, size = nrow(tobin), replace = TRUE)

# Estimate
z.out <- zelig(durable ~ age + quant, model = "tobit", data = tobin, 
                cluster = "cl", robust = TRUE)

## Error in survreg.control(...) : unused argument (cluster = "cl")