code: function CubicBezier(coordinates) {
          if (typeof coordinates === "string") {
              this.coordinates = coordinates.split(",");
          } else {
              this.coordinates = coordinates;
          }
  
          if (!this.coordinates) {
              throw "No offsets were defined";
          }
  
          this.coordinates = this.coordinates.map(function (n) { return +n; });
  
          var i;
          for (i = 3; i >= 0; i--) {
              var xy = this.coordinates[i];
              if (isNaN(xy) || (((i % 2) === 0) && (xy < 0 || xy > 1))) {
                  throw "Wrong coordinate at " + i + "(" + xy + ")";
              }
          }
      }
docs: CubicBezier object constructor
  
  @param {string|Array.number[4]} coordinates Four parameters passes to cubic-bezier()
  either in string or array format.