new_valist
Description:
Creates a new signal.
(This is usually done in the class initializer.)
See @new for details on allowed signal names.
If c_marshaller is null, g_cclosure_marshal_generic will be used as the marshaller for this 
      signal.
Parameters:
| signal_name | 
           the name for the signal  | 
      
| itype | 
           the type this signal pertains to. It will also pertain to types which are derived from this type.  | 
      
| signal_flags | 
           a combination of SignalFlags specifying detail of when the default handler is to be invoked. You should at least specify g_signal_run_first or g_signal_run_last.  | 
      
| class_closure | 
           The closure to invoke on signal emission; may be null.  | 
      
| accumulator | 
           the accumulator for this signal; may be null.  | 
      
| c_marshaller | 
           the function to translate arrays of parameter values to signal emissions into C language callback invocations or null.  | 
      
| return_type | 
           the type of return value, or g_type_none for a signal without a return value.  | 
      
| n_params | 
           the number of parameter types in   | 
      
| args | 
           va_list of Type, one for each parameter.  | 
      
| accu_data | 
           user data for the   | 
      
Returns:
| 
           the signal id  |