String getFileName(double lat, double lon) {
        int lonInt = getMinLonForTile(lon);
        int latInt = getMinLatForTile(lat);
        return toLowerCase(getLatString(latInt) + getNorthString(latInt) + getLonString(lonInt) + getEastString(lonInt) + FILE_NAME_END);
    }
@Disabled
    @Test
    public void testGetEleHorizontalBorder() {
        // Border between the tiles 50n000e and 50n030e
        assertEquals("50n000e_20101117_gmted_mea075", instance.getFileName(53, 29.999999));
        assertEquals(143, instance.getEle(53, 29.999999), precision);
        assertEquals("50n030e_20101117_gmted_mea075", instance.getFileName(53, 30.000001));
        assertEquals(142, instance.getEle(53, 30.000001), precision);
    }