Control.Concurrent.Chan: how do i close a channel?

[Claus Reinke]

in principle, Chan looks like a nice way to do pipes within
haskell code, or to avoid unsafeInterleaveIO, in combination
with getChanContents (which explicitly mentions hGetContents
in its API doc).

however, i seem to be missing a way to close a channel?
am i misinterpreting this library?

claus