@Override
    public Clob getClob(final int columnIndex) throws SQLException {
        return (Clob) mergeResultSet.getValue(columnIndex, Clob.class);
    }
@Test
    void assertGetClobWithColumnLabel() throws SQLException {
        Clob clob = mock(Clob.class);
        when(mergeResultSet.getValue(1, Clob.class)).thenReturn(clob);
        assertThat(shardingSphereResultSet.getClob("label"), is(clob));
    }