Registers @type as extension for the extension point with name @extension_point_name.
If @type has already been registered as an extension for this extension point, the existing #GIOExtension object is returned.
the name of the extension point
the #GType to register as extension
the name for the extension
the priority for the extension
a #GIOExtension object for #GType
See Implementation
Registers @type as extension for the extension point with name @extension_point_name.
If @type has already been registered as an extension for this extension point, the existing #GIOExtension object is returned.