@Override
	@SuppressWarnings("unchecked")
	public <T> T unwrap(Class<T> iface) throws SQLException {
		if (iface.isInstance(this)) {
			return (T) this;
		}
		throw new SQLException("DataSource of type [" + getClass().getName() +
				"] cannot be unwrapped as [" + iface.getName() + "]");
	}