Merge Schema::childNodes and Schema::moduleNodes

Change-Id: I30c7120fdba6c0089108599e5ab48d8dcd47f277
diff --git a/src/yang_schema.hpp b/src/yang_schema.hpp
index fb0405b..9395ba2 100644
--- a/src/yang_schema.hpp
+++ b/src/yang_schema.hpp
@@ -43,8 +43,7 @@
     yang::TypeInfo leafType(const std::string& path) const override;
     std::optional<std::string> leafTypeName(const std::string& path) const override;
     std::string leafrefPath(const std::string& leafrefPath) const override;
-    std::set<std::string> childNodes(const schemaPath_& path, const Recursion recursion) const override;
-    std::set<std::string> moduleNodes(const module_& module, const Recursion recursion) const override;
+    std::set<std::string> availableNodes(const boost::variant<dataPath_, schemaPath_, module_>& path, const Recursion recursion) const override;
     std::optional<std::string> description(const std::string& path) const override;
     yang::Status status(const std::string& location) const override;