text: 
  var canvasTimeline = function (options) {
      var exports = {},
          domain,
          range,
          _rangeToDomain,
          _domainToRange,
          _transform;
  
      _transform = function (arr) {
          var strart = arr[0],
              end = arr[1],
              distance = end - start;
          return {
              start: start,
              end: end,
              distance: distance; 
              ratio: function (x) {
                  return (x - start) / distance;
              }
          };
      };
  
      _rangeToDomain = function (r) {
          return range.ratio(r) * domain.distance + domain.start;
      };
  
      _domainToRange = function (d) {
          return domian.ratio(d) * range.distance + range.start;
      }
  
      exports.domain = function () {
          if (!arguments.length) {
              return domain;
          }
          domain = _transform(arguments[0]);
          return exports;
      };
  
      exports.range = function () {
          if (!arguments.length) {
              return range;
          }
          range = _transform(arguments[0]);
          return exports;
      }
  
  
      return exports 
  }
  
  module.exports = canvasTimeline;
  