code: function(line, bbox) {
          var prev = line[0];
          for (var i = 1; i < line.length; i++) {
              var next = line[i];
              var clipped = this.clipLine([ prev, next ], bbox);
              if (clipped) {
                  return true;
              }
              prev = next;
          }
          return false;
      }
docs: Returns true if the specified poly-line (defined as a sequence of [x,y]
  coordinates of their segments) has intersections with the specified
  bounding box.