mostly documentation mostly for Cursor, some corner cases testing

src/storage.cpp

@@ -253,6 +253,18 @@ bool LMDBAL::iStorage::isDBOpened() const {
 void LMDBAL::iStorage::throwUnknown(int rc) const {
     throw Unknown(db->name, mdb_strerror(rc), name);}
 
+/**
+ * \brief Throws LMDBAL::Unknown
+ *
+ * Helper function ment to be used in heirs and reduce the code a bit
+ *
+ * \param[in] message    - a message you wish to appear in the exception reason
+ *
+ * \exception LMDBAL::Unknown   thrown everytime
+ */
+void LMDBAL::iStorage::throwUnknown(const std::string& message) const {
+    throw Unknown(db->name, message, name);}
+
 /**
  * \brief Throws LMDBAL::Exist
  *