Add debug print

src/libmwereader/mwereader.cpp

@@ -135,6 +135,7 @@ bool MWEReader::registered = TokenReader::register_path_reader<MWEReader>(
 			tokens[head]->create_metadata();
 		}
 		TokenMetaDataPtr md = tokens[head]->get_metadata();
+		std::cout << "mwe_base: " << new_base;
 		md->set_attribute(get_annotation_channel_base_name(), new_base);
 
 		// annotate mwe elements with annotation_number of head