anchor.diff:  -spec connect_signal(Proxy :: dbus_proxy(), 
   		     IfaceName :: dbus_name(), 
   		     SignalName :: dbus_name(), 
  -		     Handler :: mfa() | {fun(), any()}) -> 
  +		     Handler :: handler()) -> 
   			    ok | {error, term()}.
   connect_signal(Proxy, IfaceName, SignalName, MFA) ->
       gen_server:call(Proxy, {connect_signal, IfaceName, SignalName, MFA}).
  
positive.code: 		     IfaceName :: dbus_name(), 
  		     SignalName :: dbus_name(), 
  		     Path :: binary(),
  		     MFA :: mfa() | {fun(), any()}) -> 
  			    ok | {error, term()}.
  connect_signal(Proxy, Service, IfaceName, SignalName, Path, MFA) ->
      gen_server:call(Proxy, {connect_signal, Service, IfaceName, SignalName, Path, MFA}).
  
negative.code: %%
  %% @doc Connect to every signal (eg for object manager)
  %%
  -spec connect_signal(Proxy :: dbus_proxy(), Handler :: handler()) -> 
  			    ok | {error, term()}.
  connect_signal(Proxy, MFA) ->
      gen_server:call(Proxy, {connect_signal, MFA}).
  