Add node-info getters to Schema

Change-Id: Iffea96cdcf20763286db19b0ee2b92dbf7c69b6c
diff --git a/src/schema.hpp b/src/schema.hpp
index a85961b..e4636cf 100644
--- a/src/schema.hpp
+++ b/src/schema.hpp
@@ -76,6 +76,8 @@
     virtual const std::set<std::string> listKeys(const schemaPath_& location, const ModuleNodePair& node) const = 0;
     virtual yang::LeafDataTypes leafType(const schemaPath_& location, const ModuleNodePair& node) const = 0;
     virtual yang::LeafDataTypes leafrefBase(const schemaPath_& location, const ModuleNodePair& node) const = 0;
+    virtual std::optional<std::string> description(const std::string& location) const = 0;
+    virtual std::optional<std::string> units(const std::string& location) const = 0;
 
     virtual const std::set<std::string> validIdentities(const schemaPath_& location, const ModuleNodePair& node, const Prefixes prefixes) const = 0;
     virtual const std::set<std::string> enumValues(const schemaPath_& location, const ModuleNodePair& node) const = 0;