int gl_graph_get_title (graph_config_t *cfg,
char *buffer, size_t buffer_size);
int gl_graph_get_title (graph_config_t *cfg,
char *buffer, size_t buffer_size);
int gl_graph_instance_get_all (graph_config_t *cfg,
gl_inst_callback callback, void *user_data);
int gl_graph_instance_get_all (graph_config_t *cfg,
gl_inst_callback callback, void *user_data);