### Question:
XYGrid implements Serializable { public double getCellWidth() { return cellWidth * OSHDB.GEOM_PRECISION; } XYGrid(final int zoom); static OSHDBBoundingBox getBoundingBox(final CellId cellID); static OSHDBBoundingBox getBoundingBox(final CellId cellID, boolean enlarge); long getId(double longitude, double latitude); long getId(long longitude, long latitude); long getId(OSHDBBoundingBox bbx); double getCellWidth(); OSHDBBoundingBox getCellDimensions(final long cellId); long getEstimatedIdCount(final OSHDBBoundingBox data); int getLevel(); Set<IdRange> bbox2CellIdRanges(OSHDBBoundingBox bbox, boolean enlarge); Set<IdRange> getNeighbours(CellId center);  }### Answer:
@Test public void testGetCellWidth() { double expResult = 90; double result = two.getCellWidth(); assertEquals(expResult, result, 0.0); }