Add Schema::leafIsKey

Will be used in the upcoming describe command.

Change-Id: Ifed7b959b235dc9cf00c896df9c9321fb155a756
diff --git a/src/static_schema.hpp b/src/static_schema.hpp
index c586083..a3ab4bc 100644
--- a/src/static_schema.hpp
+++ b/src/static_schema.hpp
@@ -54,6 +54,7 @@
     bool leafEnumHasValue(const schemaPath_& location, const ModuleNodePair& node, const std::string& value) const override;
     bool leafIdentityIsValid(const schemaPath_& location, const ModuleNodePair& node, const ModuleValuePair& value) const override;
     bool listHasKey(const schemaPath_& location, const ModuleNodePair& node, const std::string& key) const override;
+    bool leafIsKey(const std::string& leafPath) const override;
     const std::set<std::string> listKeys(const schemaPath_& location, const ModuleNodePair& node) const override;
     yang::LeafDataTypes leafType(const schemaPath_& location, const ModuleNodePair& node) const override;
     yang::LeafDataTypes leafType(const std::string& path) const override;