code: public AbstractStreamParameters addLocation(float west, float south, float east, float north) {
  		if (locations.length() > 0) {
  			locations.append(',');
  		}
  		locations.append(west).append(',').append(south).append(',');
  		locations.append(east).append(',').append(north).append(',');
  		return this;
  	}
docs: Add a location to the filter
  Does not replace any existing locations in the filter.
  @param west the longitude of the western side of the location's bounding box.
  @param south the latitude of the southern side of the location's bounding box.
  @param east the longitude of the eastern side of the location's bounding box.
  @param north the latitude of the northern side of the location's bounding box.
  @return this StreamFilter for building up filter parameters.