Implemented message source block for unit testing
diff --git a/swig/grgsm_swig.i b/swig/grgsm_swig.i
index 5dc1bcd..6189fee 100644
--- a/swig/grgsm_swig.i
+++ b/swig/grgsm_swig.i
@@ -27,6 +27,7 @@
 #include "grgsm/misc_utils/burst_sink_qa.h"
 #include "grgsm/misc_utils/burst_source.h"
 #include "grgsm/misc_utils/burst_source_qa.h"
+#include "grgsm/misc_utils/message_source.h"
 %}
 
 
@@ -72,3 +73,5 @@
 GR_SWIG_BLOCK_MAGIC2(gsm, message_printer);
 %include "grgsm/misc_utils/tmsi_dumper.h"
 GR_SWIG_BLOCK_MAGIC2(gsm, tmsi_dumper);
+%include "grgsm/misc_utils/message_source.h"
+GR_SWIG_BLOCK_MAGIC2(gsm, message_source);