func NewSourceBufferWithLanguage(lang *SourceLanguage) *SourceBuffer {
	v := C.gtk_source_buffer_new_with_language(lang.GSourceLanguage)
	return &SourceBuffer{v, gtk.NewTextBufferFromPointer(unsafe.Pointer(v))}
}
func NewSourceBuffer() *SourceBuffer {
	v := C.gtk_source_buffer_new(nil)
	return &SourceBuffer{v, gtk.NewTextBufferFromPointer(unsafe.Pointer(v))}
}