stickshift.js
function(at, lines, height) {
      this.height += height;
      this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));
      for (var i = 0; i < lines.length; ++i) lines[i].parent = this;
    }
function(at, lines, height) {
      this.height += height;
      this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));
      for (var i = 0; i < lines.length; ++i) lines[i].parent = this;
    }
function ( at , lines , height ) { this . height += height ; this . lines = this . lines . slice ( 0 , at ) . concat ( lines ) . concat ( this . lines . slice ( at ) ) ; for ( var i = 0 ; i < lines . length ; ++ i ) lines [ i ] . parent = this ; }
Insert the given array of lines at offset 'at', count them as having the given height.
Insert the given array of lines at offset at count them as having the given height .