@Override
    public URL getURL(final int columnIndex) throws SQLException {
        return (URL) mergeResultSet.getValue(columnIndex, URL.class);
    }
@Test
    void assertGetURLWithColumnIndex() throws SQLException, MalformedURLException {
        when(mergeResultSet.getValue(1, URL.class)).thenReturn(new URL("http://xxx.xxx"));
        assertThat(shardingSphereResultSet.getURL(1), is(new URL("http://xxx.xxx")));
    }