code: public ArrayList<JTSFeature> getFeatures(String id, int z, int x, int y, List<Param> optionalParams)
  			throws Exception {
  		DescribeService describeService = getDescribeServiceByID(id);
  
  		Extent e1 = TileConversor.tileOSMMercatorBounds(x, y, z);
  
  		double[] minXY = ConversionCoords.reproject(e1.getMinX(), e1.getMinY(), CRSFactory.getCRS(MERCATOR_SRS),
  				CRSFactory.getCRS(GEODETIC_SRS));
  		double[] maxXY = ConversionCoords.reproject(e1.getMaxX(), e1.getMaxY(), CRSFactory.getCRS(MERCATOR_SRS),
  				CRSFactory.getCRS(GEODETIC_SRS));
  
  		return getFeatures(id, optionalParams, describeService, minXY[0], minXY[1], maxXY[0], maxXY[1], 0, 0);
  	}
docs: This method is used to get the pois from a service and return a list of
  {@link JTSFeature} document with the data retrieved given a Z/X/Y tile.
  
  @param id
  The id of the service
  @param z
  The zoom level
  @param x
  The x tile
  @param y
  The y tile
  @return a list of {@link JTSFeature}