Gets a pointer to native credentials of type @native_type from
@credentials.
It is a programming error (which will cause a warning to be
logged) to use this method if there is no #GCredentials support for
the OS or if @native_type isn't supported by the OS.
The pointer to native credentials or
%NULL if there is no #GCredentials support for the OS or if @native_type
isn't supported by the OS. Do not free the returned data, it is owned
by @credentials.
Gets a pointer to native credentials of type @native_type from @credentials.
It is a programming error (which will cause a warning to be logged) to use this method if there is no #GCredentials support for the OS or if @native_type isn't supported by the OS.