code: public static Long getApproximateZoomLevel(double[] widths,
  			double[] heights, List<TileMatrix> tileMatrices, double length) {
  		return getApproximateZoomLevel(widths, heights, tileMatrices, length,
  				length);
  	}
docs: Get the approximate zoom level for the provided length in the default
  units. Tiles may or may not exist for the returned zoom level. The
  approximate zoom level is determined using a factor of 2 from the zoom
  levels with tiles.
  
  @param widths
  sorted widths
  @param heights
  sorted heights
  @param tileMatrices
  tile matrices
  @param length
  length in default units
  @return actual or approximate tile matrix zoom level
  @since 2.0.2