### Question:
GeoHash { public static boolean hashContains(String hash, double lat, double lon) { LatLong centre = decodeHash(hash); return Math.abs(centre.getLat() - lat) <= heightDegrees(hash.length()) / 2 && Math.abs(to180(centre.getLon() - lon)) <= widthDegrees(hash.length()) / 2; } private  GeoHash(); static String adjacentHash(String hash, Direction direction); static String right(String hash); static String left(String hash); static String top(String hash); static String bottom(String hash); static String adjacentHash(String hash, Direction direction, int steps); static List<String> neighbours(String hash); static String encodeHash(double latitude, double longitude); static String encodeHash(LatLong p, int length); static String encodeHash(LatLong p); static String encodeHash(double latitude, double longitude, int length); static LatLong decodeHash(String geohash); static int hashLengthToCoverBoundingBox(double topLeftLat, double topLeftLon,
            double bottomRightLat, double bottomRightLon); static boolean hashContains(String hash, double lat, double lon); static Coverage coverBoundingBox(double topLeftLat, final double topLeftLon,
            final double bottomRightLat, final double bottomRightLon); static Coverage coverBoundingBoxMaxHashes(double topLeftLat, final double topLeftLon,
            final double bottomRightLat, final double bottomRightLon, int maxHashes); static Coverage coverBoundingBox(double topLeftLat, final double topLeftLon,
            final double bottomRightLat, final double bottomRightLon, final int length); static double heightDegrees(int n); static double widthDegrees(int n); static String gridAsString(String hash, int size, Set<String> highlightThese); static String gridAsString(String hash, int fromRight, int fromBottom, int toRight,
            int toBottom); static String gridAsString(String hash, int fromRight, int fromBottom, int toRight,
            int toBottom, Set<String> highlightThese); static final int MAX_HASH_LENGTH; static final int DEFAULT_MAX_HASHES; }### Answer:
@Test public void testHashContains() { LatLong centre = decodeHash("dre7"); assertTrue(GeoHash.hashContains("dre7", centre.getLat(), centre.getLon())); assertFalse(GeoHash.hashContains("dre7", centre.getLat() + 20, centre.getLon())); assertFalse(GeoHash.hashContains("dre7", centre.getLat(), centre.getLon() + 20)); }