Use ListInstance typedef in more places

Change-Id: Ic41218a1e09f76d7455816163d9b3ca24b0b94ca
diff --git a/src/ast_handlers.cpp b/src/ast_handlers.cpp
index f160d8c..b77964b 100644
--- a/src/ast_handlers.cpp
+++ b/src/ast_handlers.cpp
@@ -1,5 +1,5 @@
 #include "ast_handlers.hpp"
-std::set<Completion> generateMissingKeyCompletionSet(std::set<std::string> keysNeeded, std::map<std::string, leaf_data_> currentKeys)
+std::set<Completion> generateMissingKeyCompletionSet(std::set<std::string> keysNeeded, ListInstance currentKeys)
 {
     std::set<std::string> missingKeys;