The XMethod is used to precise the arguments and the result type of
a method defined in a class inherited from XObject
(see section about XObject for more precisions),
there is no interest to use this class directly ...
The name is mandatory and must be a non-empty string.
The optional in_xattributes member is a list of XAttribute instances.
The optional out_xtype member is a XType instance which
precise what is the result type.