@Override
    public double getDouble(final int columnIndex) throws SQLException {
        return (double) ResultSetUtils.convertValue(mergeResultSet.getValue(columnIndex, double.class), double.class);
    }
@Test
    void assertGetDoubleWithColumnIndex() throws SQLException {
        when(mergeResultSet.getValue(1, double.class)).thenReturn(1.0D);
        assertThat(shardingSphereResultSet.getDouble(1), is(1.0D));
    }