get-surrounding-text test for ibus-m17n

diff --git a/src/engine.c b/src/engine.c
index dcfbe48..ed82f43 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -623,6 +623,12 @@ ibus_m17n_engine_callback (MInputContext *context,
     else if (command == Minput_reset) {
     }
     else if (command == Minput_get_surrounding_text) {
+      gchar *text;
+      gint cursor_index;
+      ibus_engine_get_surrounding_text ((IBusEngine *) m17n, &text,
+                                       &cursor_index);
+      g_print ("ibus_engine_get_surrounding_text ('%s', %d)\n",
+              text, cursor_index);
     }
     else if (command == Minput_delete_surrounding_text) {
     }