check = function(expected, ranges) {
    var set = new lf.index.SingleKeyRangeSet(ranges);
    assertTrue(expected.equals(/** @type {!lf.index.SingleKeyRange} */ (
        set.getBoundingRange())));
  }
@param {!lf.index.SingleKeyRange} expected
@param {!Array<!lf.index.SingleKeyRange>} ranges