_sasl_common_init
ret = _sasl_common_init(gctx, &gctx->client_global_callbacks, 0);
ret = _sasl_common_init(&global_callbacks);
extern int _sasl_common_init(_sasl_global_context_t *gctx,
extern int _sasl_common_init(sasl_global_callbacks_t *global_callbacks);
ret = _sasl_common_init(gctx, &gctx->server_global_callbacks, 1);
ret = _sasl_common_init(&global_callbacks);