9.0+ way of determining if a LISTEN channel has a backend listening?

Is there a way in post-9.0 postgres for one session to determine if a  
LISTEN channel currently has a backend registered to receive  
notifications? Prior to 9.0, one could select from system catalog  
table pg_listener.

Function pg_listening_channels() returns list of symbol names *this*  
session is listening on; I'd like to find out if a given listen  
channel has *any* (i.e other session) listeners.

Thanks!
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James Robinson
Socialserve.com