Copies the native credentials of type @native_type from @native
into @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.
Copies the native credentials of type @native_type from @native into @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.