[R] error with subtree()

[Fix Ace]

Dear R community,
I would like to plot a partial hclust output, so I am looking for a subtree function that would return an tree structure I can plot.
I ran the test code of subtree following the instruction on http://finzi.psych.upenn.edu/library/extracat/html/subtree.html
However, an error message popped up:
====> library(extracat)
Attaching package: ‘extracat’
The following object is masked _by_ ‘.GlobalEnv’:
    subtreehc <- hclust(dist(USArrests), "ave")> > hcs <- subtree(hc, k = 7)Error in subtree(hc, k = 7) : unused argument (k = 7)
===
Can anyone help me what happened here? And what should I do with it?
Thank you very much!
Ace

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