### Question:
UtmConverter { public static int utmZone(GeoCoordinate coordinate) { Validate.notNull(coordinate, "coordinate must not be null"); double lat = coordinate.getLatitude(); double lng = coordinate.getLongitude(); int zone = (int)floor((lng + 180.0) / 6) + 1; if (lat >= 56.0 && lat < 64.0 && lng >= 3.0 && lng < 12.0) { zone = 32; } if (lat >= 72.0 && lat < 84.0) { if (lng >= 0.0 && lng < 9.0) { zone = 31; } else if (lng >= 9.0 && lng < 21.0) { zone = 33; } else if (lng >= 21.0 && lng < 33.0) { zone = 35; } else if (lng >= 33.0 && lng < 42.0) { zone = 37; } } return zone; } private  UtmConverter(); static UtmCoordinate toUtm(GeoCoordinate coordinate); static GeoCoordinate toLatLon(double easting, double northing, int zone, boolean southHemi); static int utmZone(GeoCoordinate coordinate); static char utmBand(double lat); static GeoCoordinate gridZoneToLatLon(String gridZone);  }### Answer:
@Test public void testUtmZone() { assertEquals(33, UtmConverter.utmZone(new ImmutableGeoCoordinate(51.049259, 13.73836))); }