A convenience macro to ease adding private data to instances of a new dynamic
type in the
_C_ section of G_DEFINE_DYNAMIC_TYPE_EXTENDED().
See G_ADD_PRIVATE() for details, it is similar but for static types.
Note that this macro can only be used together with the G_DEFINE_DYNAMIC_TYPE_EXTENDED macros, since it depends on variable names from that macro.
Available since: 2.38
This function is not directly available to language bindings.