code: function (x1, y1, x2, y2) {
      return new BVG('line', x1.constructor.name === 'Object' ? x1 : {
        x1: x1,
        y1: y1,
        x2: x2,
        y2: y2
      });
    }
docs: ### `bvg.line(x1, y1, x2, y2)`
  Create a line from `(x1, y1)` to `(x2, y2)`.
  
  ```Javascript
  var line = bvg.line(100, 100, 200, 300);
  ```