(PECL gupnp >= 0.1.0)
gupnp_service_proxy_callback_set — Set service proxy callback for signal
$proxy
   , int $signal
   , mixed $callback
   [, mixed $arg
  ] )Set service proxy callback for signal.
proxyA service proxy identifier.
signalThe value of signal.
GUPNP_SIGNAL_SUBSCRIPTION_LOSTcallback
       The callback function for the certain signal. Typically, callback function 
       takes on two parameters.  error parameter's message 
       being the first, and the arg is second.
      
arg
       User data for callback. 
      
   Returns TRUE on success or FALSE on failure.
  
Issues E_WARNING either with not valid callback function or with not valid signal.