public <T> T unwrap(Class<T> iface) throws SQLException {
        return null;
    }
Retrieves the value of the designated column in the current row
of this <code>ResultSet</code> object as a <code>NClob</code> object
in the Java programming language.

@param colName the name of the column from which to retrieve the value
@return a <code>NClob</code> object representing the SQL <code>NCLOB</code>
value in the specified column
@exception SQLException if a database access error occurs
@since 6.0
src/main/java/org/replicadb/rowset/sun/rowset/CachedRowSetImpl.java