docs: function round10(value, exp) {
                  var type = 'round';
                  // If the exp is undefined or zero...
                  if (typeof exp === 'undefined' || +exp === 0) {
                      return Math[type](value);
                  }
                  value = +value;
                  exp = +exp;
                  // If the value is not a number or the exp is not an integer...
                  if (isNaN(value) || !(typeof exp === 'number' && exp % 1 === 0)) {
                      return NaN;
                  }
                  // Shift
                  value = value.toString().split('e');
                  value = Math[type](+(value[0] + 'e' + (value[1] ? (+value[1] - exp) : -exp)));
                  // Shift back
                  value = value.toString().split('e');
                  return +(value[0] + 'e' + (value[1] ? (+value[1] + exp) : exp));
              }